Exhibit 3.1

THIRD AMENDED AND RESTATED BY-LAWS

OF

IPC THE HOSPITALIST COMPANY, INC.,

A DELAWARE CORPORATION

TABLE OF CONTENTS

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THIRD AMENDED AND RESTATED BY-LAWS

OF

IPC THE HOSPITALIST COMPANY, INC.,

A DELAWARE CORPORATION

ARTICLE I

Stockholders Meetings

Section 1.1 Annual Meetings.

(a) An annual meeting of stockholders shall be held for the election of directors and the transaction of such other business as may properly be brought before the meeting in accordance with these By-laws at such date, time and place, if any, as may be fixed by resolution of the Board of Directors of the Corporation from time to time. The Board of Directors may, in its sole discretion, determine that the meeting shall not be held at any place, but shall be held solely by means of remote communication, subject to such guidelines and procedures as the Board of Directors may adopt, as permitted by applicable law. Subject to paragraphs (b) and (c) of this Section 1.1, any other proper business may be transacted at an annual meeting.

(b) Only such business shall be conducted at an annual meeting of stockholders as shall have been properly brought before the meeting. For business to be properly brought before the meeting, it must be: (i) authorized by the Board of Directors and specified in the notice, or a supplemental notice, of the meeting, (ii) otherwise brought before the meeting by or at the direction of the Board of Directors or the chairman of the meeting, or (iii) otherwise properly brought before the meeting by a stockholder (A) who is a stockholder of record on the date of the giving of the notice provided for in this Section 1.1, on the record date for the determination of stockholders entitled to notice of and to vote at such annual meeting, and at the time of such annual meeting, (B) who is entitled to vote at such annual meeting and (C) who complies with the notice procedures set forth in this Section 1.1.

(c) For business to be properly brought before an annual meeting by a stockholder pursuant to clause (iii) of paragraph (b) of this Section 1.1, the stockholder must have given written notice thereof to the Secretary of the Corporation, delivered or mailed to and received at the principal executive offices of the Corporation not less than 90 days nor more than 120 days prior to the anniversary date of the immediately preceding annual meeting; provided, however, that in the event that no annual meeting was held in the previous year or the annual meeting is called for a date that is not within 30 days from the anniversary date of the preceding year’s annual meeting date, written notice by a stockholder in order to be timely must be received not later than the close of business on the tenth day following the day on which the first public disclosure of the date of the annual meeting was made. Delivery shall be by hand or by certified or registered mail, return receipt requested. In no event shall the public disclosure of an

adjournment of an annual meeting commence a new time period for the giving of stockholder’s notice as described above. A stockholder’s notice to the Secretary shall set forth as to each item of business the stockholder proposes to bring before the meeting: (1) a description of such item and the reasons for conducting such business at the meeting, (2) the name and address, as they appear on the Corporation’s records, of the stockholder proposing such business, (3) a representation that the stockholder is a holder of record of shares of stock of the Corporation entitled to vote with respect to such business and intends to appear in person or by proxy at the meeting to move the consideration of such business, (4) (A) the class and number of shares of stock of the Corporation which are owned, directly or indirectly, beneficially or of record by the stockholder (for purposes of the regulations under Sections 13 and 14 of the Securities Exchange Act of 1934, as amended (such act, and the rules and regulations promulgated thereunder, the “Exchange Act”)) and (B) any derivative positions held or beneficially held by such stockholder and whether and the extent to which any hedging or other transaction or series of transactions has been entered into by or on behalf of, or any other agreement, arrangement or understanding (including, without limitation, any short position or any borrowing or lending of shares) has been made, the effect or intent of which is to mitigate loss to or manage risk or benefit of share price changes for, or to increase or decrease the voting power of, any such stockholder with respect to shares of the Corporation (which information described in this clause (4) shall be supplemented by such stockholder not later than ten (10) days after the record date for the meeting to disclose such ownership as of the record date), (5) a description of all arrangements or understandings between such stockholder and any other person or persons (including their names) in connection with the proposal of such business by such stockholder and any material interest of such stockholder in such business, (6) a representation as to whether or not such stockholder will deliver a proxy statement and form of proxy to the holders of at least the percentage of the Corporation’s voting shares required under applicable law to adopt such proposed business or otherwise to solicit proxies from stockholders in support of such proposal, and (7) any other information relating to such stockholder that would be required to be disclosed in a proxy statement or other filings required to be made in connection with solicitations of proxies for stockholder proposals pursuant to Section 14 of the Exchange Act. No business shall be conducted at any annual meeting except in accordance with the procedures set forth in paragraphs (b) and (c) of this Section 1.1, and, for the avoidance of doubt, clause (iii) of paragraph (b) of this Section 1.1 shall be the exclusive means for a stockholder to propose business (other than business included in the Corporation’s proxy materials pursuant to Rule 14a-8 under the Exchange Act) at an annual meeting of stockholders. The chairman of the meeting at which any business is proposed by a stockholder shall, if the facts warrant, determine and declare to the meeting that such business was not properly brought before the meeting in accordance with the provisions of this paragraph (b), and, in such event, the business not properly before the meeting shall not be transacted.

Section 1.2 Special Meetings. Special meetings of stockholders for any purpose or purposes may be called at any time only pursuant to a resolution approved by a majority of the whole Board of Directors and by no other person. The Board of Directors may, in its sole discretion, determine that the special meeting shall not be held at any place, but shall be held solely by means of remote communication, subject to such guidelines and procedures as the Board of Directors may adopt, as permitted by applicable law. The business transacted at a special meeting of stockholders shall be limited solely to matters relating to the purpose or purposes stated in the Corporation’s notice of meeting.

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Section 1.3 Notice of Meetings. A written notice of each annual or special meeting of stockholders shall be given stating the place, if any, date and time of the meeting, the means of remote communications, if any, by which stockholders and proxyholders may be deemed to be present in person and vote at such meeting and, in the case of a special meeting, the purpose or purposes for which the meeting is called. Unless otherwise provided by law, the Certificate of Incorporation or these By-laws, such notice of meeting shall be given not less than ten nor more than 60 days before the date of the meeting to each stockholder of record entitled to vote at such meeting, personally, by mail or, to the extent and in the manner permitted by applicable law, electronically. If mailed, such notice shall be deemed to be given when deposited in the mail, postage prepaid, directed to the stockholder at such stockholder’s address as it appears on the records of the Corporation.

Section 1.4 Postponements and Adjournments. The Board of Directors may postpone a previously scheduled meeting so long as notice of the postponement is given pursuant to Section 1.3 not less than 24 hours prior to the scheduled meeting date. Such notice of postponement shall include the place, if any, and the new date and time of the meeting. Any annual or special meeting of stockholders may be adjourned by the chairman of the meeting from time to time to reconvene at the same or some other place, if any, and notice need not be given of any such adjourned meeting if the date, time and place, if any, thereof and the means of remote communication, if any, by which stockholders and proxyholders may be deemed present in person and vote at such adjourned meeting are announced at the meeting at which the adjournment is taken. At the adjourned meeting any business may be transacted which might have been transacted at the original meeting. If the adjournment is for more than 30 days, or if after the adjournment a new record date is fixed for the adjourned meeting, a notice of the adjourned meeting shall be given to each stockholder of record entitled to vote at the adjourned meeting in accordance with Section 1.3.

Section 1.5 Quorum. Except as otherwise provided by law, the Certificate of Incorporation or these By-laws, the presence in person or by proxy of the holders of stock having a majority of the votes which could be cast by the holders of all outstanding stock entitled to vote at the meeting shall constitute a quorum at each meeting of stockholders. In the absence of a quorum, the stockholders so present may, by the affirmative vote of the holders of stock having a majority of the votes which could be cast by all such holders, adjourn the meeting from time to time in the manner provided in Section 1.4 of these By-laws until a quorum is present. If a quorum is present when a meeting is convened, the subsequent withdrawal of stockholders, even though less than a quorum remains, shall not affect the ability of the remaining stockholders lawfully to transact business.

Section 1.6 Conduct; Remote Communication.

(a) Meetings of stockholders shall be presided over by the Chairman of the Board, if any, or if there is none or in his or her absence, by the President, or in his or her absence, by a chairman designated by the Board of Directors, or in the absence of such designation by a chairman chosen at the meeting. The Secretary shall act as secretary of the meeting, but in his or her absence the chairman of the meeting may appoint any person to act as secretary of the meeting.

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(b) If authorized by the Board of Directors in accordance with these By-laws and applicable law, stockholders and proxyholders not physically present at a meeting of stockholders may, by means of remote communication, (1) participate in a meeting of stockholders and (2) be deemed present in person and vote at a meeting of stockholders, whether such meeting is to be held at a designated place or solely by means of remote communication, provided that (i) the Corporation shall implement reasonable measures to verify that each person deemed present and permitted to vote at the meeting by means of remote communication is a stockholder or proxyholder, (ii) the Corporation shall implement reasonable measures to provide such stockholders and proxyholders a reasonable opportunity to participate in the meeting and to vote on matters submitted to the stockholders, including an opportunity to read or hear the proceedings of the meeting substantially concurrently with such proceedings, and (iii) if any stockholder or proxyholder votes or takes other action at the meeting by means of remote communication, a record of such vote or other action shall be maintained by the Corporation.

Section 1.7 Voting.

(a) Except as otherwise provided by the Certificate of Incorporation, each stockholder entitled to vote at any meeting of stockholders shall be entitled to one vote for each share of stock held by such stockholder which has voting power on the matter in question.

(b) Voting at meetings of stockholders need not be by written ballot and need not be conducted by inspectors of election unless so required by Section 1.9 of these By-laws or so determined by the holders of stock having a majority of the votes which could be cast by the holders of all outstanding stock entitled to vote which are present in person or by proxy at such meeting. Unless otherwise provided in the Certificate of Incorporation, directors shall be elected by a plurality of the votes cast in the election of directors. Each other question shall, unless otherwise provided by law, the Certificate of Incorporation or these By-laws, be decided by the vote of the holders of stock having a majority of the votes which could be cast by the holders of all stock entitled to vote on such question which are present in person or by proxy at the meeting.

(c) Stock of the Corporation standing in the name of another corporation and entitled to vote may be voted by such officer, agent or proxy as the By-laws or other internal regulations of such other corporation may prescribe or, in the absence of such provision, as the board of directors or comparable body of such other corporation may determine.

(d) Stock of the Corporation standing in the name of a deceased person, a minor, an incompetent or a debtor in a case under Title 11, United States Code, and entitled to vote may be voted by an administrator, executor, guardian, conservator, debtor-in-possession or trustee, as the case may be, either in person or by proxy, without transfer of such shares into the name of the official or other person so voting.

(e) A stockholder whose voting stock of the Corporation is pledged shall be entitled to vote such stock unless on the transfer records of the Corporation the pledgor has expressly empowered the pledgee to vote such shares, in which case only the pledgee, or such pledgee’s proxy, may represent such shares and vote thereon.

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(f) If voting stock is held of record in the names of two or more persons, whether fiduciaries, members of a partnership, joint tenants, tenants in common, tenants by the entirety or otherwise, or if two or more persons have the same fiduciary relationship respecting the same shares, unless the Secretary is given written notice to the contrary and is furnished with a copy of the instrument or order appointing them or creating the relationship wherein it is so provided, their acts with respect to voting shall have the following effect: (i) if only one votes, such act binds all; (ii) if more than one vote, the act of the majority so voting binds all; and (iii) if more than one votes, but the vote is evenly split on any particular matter each faction may vote such stock proportionally, or any person voting the shares, or a beneficiary, if any, may apply to the Court of Chancery of the State of Delaware or such other court as may have jurisdiction to appoint an additional person to act with the persons so voting the stock, which shall then be voted as determined by a majority of such persons and the person appointed by the Court. If the instrument so filed shows that any such tenancy is held in unequal interests, a majority or even split for the purpose of this subsection shall be a majority or even split in interest.

(g) Stock of the Corporation belonging to the Corporation, or to another corporation a majority of the shares entitled to vote in the election of directors of which are held by the Corporation, shall not be voted at any meeting of stockholders and shall not be counted in the total number of outstanding shares for the purpose of determining whether a quorum is present. Nothing in this Section 1.7 shall limit the right of the Corporation to vote shares of stock of the Corporation held by it in a fiduciary capacity.

Section 1.8 Proxies.

(a) Each stockholder entitled to vote at a meeting of stockholders may authorize another person or persons to act for such stockholder by proxy filed with the Secretary before or at the time of the meeting. No such proxy shall be voted or acted upon after three years from its date, unless the proxy provides for a longer period. A duly executed proxy shall be irrevocable if it states that it is irrevocable and if, and only as long as, it is coupled with an interest sufficient in law to support an irrevocable power. A stockholder may revoke any proxy which is not irrevocable by attending the meeting and voting in person or by filing with the Secretary an instrument in writing revoking the proxy or another duly executed proxy bearing a later date.

(b) A stockholder may authorize another person or persons to act for such stockholder as proxy (i) by executing a writing authorizing such person or persons to act as such, which execution may be accomplished by such stockholder or such stockholder’s authorized officer, director, partner, employee or agent (or, if the stock is held in a trust or estate, by a trustee, executor or administrator thereof) signing such writing or causing his or her signature to be affixed to such writing by any reasonable means, including, but not limited to, facsimile signature, or (ii) by transmitting or authorizing the transmission of a telegram, cablegram or other means of electronic transmission (a “Transmission”) to the person who will be the holder of the proxy or to a proxy solicitation firm, proxy support service organization or like agent duly authorized by the person who will be the holder of the proxy to receive such Transmission; provided that any such Transmission must either set forth or be submitted with information from which it can be determined that such Transmission was authorized by such stockholder.

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(c) Any inspector or inspectors appointed pursuant to Section 1.9 of these By-laws shall examine Transmissions to determine if they are valid. If no inspector or inspectors are so appointed, the Secretary or such other person or persons as shall be appointed from time to time by the Board of Directors shall examine Transmissions to determine if they are valid. If it is determined that a Transmission is valid, the person or persons making that determination shall specify the information upon which such person or persons relied. Any copy, facsimile telecommunication or other reliable reproduction of such a writing or Transmission may be substituted or used in lieu of the original writing or Transmission for any and all purposes for which the original writing or Transmission could be used; provided that such copy, facsimile telecommunication or other reproduction shall be a complete reproduction of the entire original writing or Transmission.

Section 1.9 Voting Procedures and Inspectors of Elections.

(a) If the Corporation has a class of voting stock that is (i) listed on a national securities exchange, (ii) authorized for quotation on an interdealer quotation system of a registered national securities association or (iii) held of record by more than 2,000 stockholders, the Board of Directors shall, in advance of any meeting of stockholders, appoint one or more inspectors (individually an “Inspector,” and collectively the “Inspectors”) to act at such meeting and make a written report thereof. The Board of Directors may designate one or more persons as alternate Inspectors to replace any Inspector who shall fail to act. If no Inspector or alternate is able to act at such meeting, the chairman of the meeting shall appoint one or more other persons to act as Inspectors. Each Inspector, before entering upon the discharge of his or her duties, shall take and sign an oath faithfully to execute the duties of Inspector with strict impartiality and according to the best of his or her ability.

(b) The Inspectors shall (i) ascertain the number of shares of stock of the Corporation outstanding and the voting power of each, (ii) determine the number of shares of stock of the Corporation present in person or by proxy at such meeting and the validity of proxies and ballots, (iii) count all votes and ballots, (iv) determine and retain for a reasonable period of time a record of the disposition of any challenges made to any determination by the Inspectors and (v) certify their determination of the number of such shares present in person or by proxy at such meeting and their count of all votes and ballots. The Inspectors may appoint or retain other persons or entities to assist them in the performance of their duties.

(c) Unless otherwise provided by the Board of Directors, the date and time of the opening and the closing of the polls for each matter upon which the stockholders will vote at a meeting shall be established at the sole discretion of the chairman of the meeting and announced at such meeting. No ballots, proxies or votes, nor any revocations thereof or changes thereto, shall be accepted by the Inspectors after the closing of the polls unless the Court of Chancery of the State of Delaware upon application by the Corporation or any stockholder shall determine otherwise.

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(d) In determining the validity and counting of proxies and ballots, the Inspectors shall be limited to an examination of the proxies, any envelopes submitted with such proxies, any information referred to in paragraphs (b) and (c) of Section 1.8 of these By-laws, ballots and the regular books and records of the Corporation, except that the Inspectors may consider other reliable information for the limited purpose of reconciling proxies and ballots submitted by or on behalf of banks, brokers, their nominees or similar persons which represent more votes than the holder of a proxy is authorized by a stockholder of record to cast or more votes than such stockholder holds of record. If the Inspectors consider other reliable information for the limited purpose permitted herein, the Inspectors, at the time they make their certification pursuant to paragraph (b) of this Section 1.9, shall specify the precise information considered by them, including the person or persons from whom such information was obtained, when and the means by which such information was obtained and the basis for the Inspectors’ belief that such information is accurate and reliable.

Section 1.10 Fixing Date of Determination of Stockholders of Record.

(a) In order that the Corporation may determine the stockholders entitled (i) to notice of or to vote at any meeting of stockholders or any adjournment thereof, (ii) to receive payment of any dividend or other distribution or allotment of any rights, (iii) to exercise any rights in respect of any change, conversion or exchange of stock, or (iv) to take, receive or participate in any other action, the Board of Directors may fix a record date, which shall not be earlier than the date upon which the resolution fixing the record date is adopted by the Board of Directors and which (1) in the case of a determination of stockholders entitled to notice of or to vote at any meeting of stockholders or adjournment thereof, shall, unless otherwise required by law, be not more than 60 nor less than ten days before the date of such meeting; and (2) in the case of any other action, shall be not more than 60 days before such action.

(b) If no record date is fixed, (i) the record date for determining stockholders entitled to notice of or to vote at a meeting of stockholders shall be at the close of business on the day next preceding the day on which notice is given, or, if notice is waived, at the close of business on the day next preceding the day on which the meeting is held; and (ii) the record date for determining stockholders for any other purpose shall be at the close of business on the day on which the Board of Directors adopts the resolution relating thereto.

(c) A determination of stockholders of record entitled to notice of or to vote at a meeting of stockholders shall apply to any adjournment of the meeting, but the Board of Directors may fix a new record date for the adjourned meeting.

Section 1.11 List of Stockholders Entitled to Vote. The Secretary shall prepare, at least ten days before every meeting of stockholders, a complete list of the stockholders entitled to vote at the meeting, arranged in alphabetical order, and showing the address and the number of shares registered in the name of each stockholder. Such list shall be open to the examination of any stockholder, for any purpose germane to the meeting for a period of at least ten days prior to the meeting: (i) on a reasonably accessible electronic network, provided that the information required to gain access to such list is provided with the notice of the meeting, or (ii) during ordinary business hours, at the principal place of business of the Corporation. In the event that the Corporation determines to make the list available on an electronic network, the Corporation

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may take reasonable steps to ensure that such information is available only to stockholders of the Corporation. If the meeting is to be held at a place, the list shall also be produced and kept at the time and place of the meeting during the whole time thereof and may be inspected by any stockholder who is present. If the meeting is to be held solely by means of remote communication, the list shall be open to the examination of any stockholder during the whole time thereof on a reasonably accessible electronic network, and the information required to access such list shall be provided with the notice of the meeting. The stock ledger shall be the only evidence as to who are the stockholders entitled to examine the stock ledger, the list of stockholders or the books of the Corporation, or to vote in person or by proxy at any meeting of stockholders.

ARTICLE II

Board of Directors

Section 2.1 Election; Resignation; Vacancies.

(a) At each annual meeting at which the term of office of a class of directors expires, the stockholders shall elect directors of such class each to hold office until the annual meeting at which the terms of office of such class of directors expire and the election and qualification of his or her successor, or until his or her earlier death, resignation or removal.

(b) Only persons who are nominated in accordance with the procedures set forth in paragraphs (b) and (c) of this Section 2.1 shall be eligible for election as directors of the Corporation. Nominations of persons for election to the Board of Directors may be made at a meeting of stockholders (1) by the Board of Directors or (2) by any stockholder of the Corporation (A) who is a stockholder of record on the date of the giving of the notice provided for in this Section 2.1, on the record date for the determination of stockholders entitled to notice of and to vote at such annual or special meeting, and at the time of such annual or special meeting, (B) who is entitled to vote in the election of directors at such annual or special meeting and (C) who complies with the notice procedures set forth in this Section 2.1.

(c) Any nomination by a stockholder must be made by written notice to the Secretary delivered or mailed to and received at the principal executive offices of the Corporation: (i) with respect to an election to be held at an annual meeting of stockholders, not less than 90 days nor more than 120 days prior to the anniversary date of the immediately preceding annual meeting; provided, however, that in the event that no annual meeting was held in the previous year or the annual meeting is called for a date that is not within 30 days from the anniversary date of the preceding year’s annual meeting date, written notice by the stockholder in order to be timely must be so received not later than the close of business on the tenth day following the day on which public disclosure of the date of the annual meeting was made, and (ii) with respect to an election to be held at a special meeting of stockholders called for the purpose of electing directors, not later than the close of business on the tenth day following the day on which the first public disclosure of the date of the special meeting was made. Delivery shall be by hand, or by certified or registered mail, return receipt requested. In no event shall the public announcement of an adjournment of any annual or special meeting commence a new time

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period for giving of a stockholder notice as described above. A stockholder’s notice to the Secretary shall set forth (x) as to each person whom the stockholder proposes to nominate for election or re-election as a director: (1) the name, age, business address and residence address of such person, (2) the principal occupation or employment of such person, (3) the class and number of shares of stock of the Corporation which are beneficially owned by such person (for the purposes of the regulations under Sections 13 and 14 of the Exchange Act , (4) any other information relating to such person that would be required to be disclosed in solicitations of proxies for the election of such person as a director of the Corporation pursuant to Regulation 14A under the Exchange Act , had the nominee been nominated by the Board of Directors, and (5) such person’s written consent to being named in any proxy statement as a nominee and to serving as a director if elected; and (y) as to the stockholder giving notice: (1) the name and address, as they appear on the Corporation’s records, of such stockholder, (2) (A) the class and number of shares of stock of the Corporation which are owned, directly or indirectly, beneficially or of record by the stockholder (for purposes of the regulations under Sections 13 and 14 of the Exchange Act) and (B) any derivative positions held or beneficially held by such stockholder and whether and the extent to which any hedging or other transaction or series of transactions has been entered into by or on behalf of, or any other agreement, arrangement or understanding (including, without limitation, any short position or any borrowing or lending of shares) has been made, the effect or intent of which is to mitigate loss to or manage risk or benefit of share price changes for, or to increase or decrease the voting power of, any such stockholder with respect to shares of the Corporation (which information described in this clause (2) shall be supplemented by such stockholder not later than ten (10) days after the record date for the meeting to disclose such ownership as of the record date), (3) a representation that the stockholder is a holder of record of stock of the Corporation entitled to vote on the election of directors at such meeting and that such stockholder intends to appear in person or by proxy at the meeting to nominate the person or persons specified in the notice, (4) a description of all agreements, arrangements or understandings between the stockholder and each nominee of the stockholder and any other person or persons (naming such person or persons) pursuant to which the nomination or nominations are to be made by the stockholder, (5) a representation as to whether or not such stockholder will deliver a proxy statement and form of proxy to a number of holders of the Corporation’s voting shares reasonably believed by such stockholder to be sufficient to elect its nominee or nominees or otherwise to solicit proxies from stockholders in support of such nominations, and (6) any other information relating to such stockholder that would be required to be disclosed in a proxy statement or other filings required to be made in connection with solicitations of proxies for election of directors pursuant to Regulation 14A under the Exchange Act. At the request of the Board of Directors any person nominated by the Board of Directors for election as a director shall furnish to the Secretary that information required to be set forth in a stockholder’s notice of nomination which pertains to the nominee. The Corporation may require any proposed nominee to furnish such other information as may reasonably be required by the Corporation to determine the eligibility of such proposed nominee to serve as a director of the Corporation. The chairman of the meeting at which a stockholder nomination is presented shall, if the facts warrant, determine and declare to the meeting that such nomination was not made in accordance with the procedures prescribed by this paragraph (c), and, in such event, the defective nomination shall be disregarded.

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(d) Any director may resign at any time by giving written notice to the Chairman of the Board, if any, the President or the Secretary. A resignation shall take effect when the resignation is delivered to the officer to whom it is directed unless the resignation specifies a later effective date or an effective date determined upon the happening of an event or events, without any need for its acceptance. A resignation that is conditioned upon the director failing to receive a specified vote for reelection as a director may provide that it is irrevocable.

Section 2.2 Regular Meetings. Unless otherwise determined by the Board of Directors, a regular annual meeting of the Board of Directors shall be held, without call or notice, immediately after and, if the annual meeting of stockholders is held at a place, at the same place as the annual meeting of stockholders, for the purpose of organizing the Board of Directors, electing officers and transacting any other business that may properly come before such meeting. Additional regular meetings of the Board of Directors may be held without call or notice at such times as shall be fixed by resolution of the Board of Directors.

Section 2.3 Special Meetings. Special meetings of the Board of Directors may be called by the Chairman of the Board, if any, the President, the Secretary or by any member of the Board of Directors. Notice of a special meeting of the Board of Directors shall be given by the person or persons calling the meeting at least twenty-four hours before the special meeting. The purpose or purposes of a special meeting need not be stated in the call or notice.

Section 2.4 Organization. Meetings of the Board of Directors shall be presided over by the Chairman of the Board, if any, or if there is none or in his or her absence, by the President, or in his or her absence, by a chairman chosen at the meeting. The Secretary shall act as secretary of the meeting, but in his or her absence the chairman of the meeting may appoint any person to act as secretary of the meeting. A majority of the directors present at a meeting, whether or not they constitute a quorum, may adjourn such meeting to any other date, time or place without notice other than announcement at the meeting.

Section 2.5 Quorum; Vote Required for Action. At all meetings of the Board of Directors a majority of the whole Board of Directors shall constitute a quorum for the transaction of business. Unless the Certificate of Incorporation or these By-laws otherwise provide, the vote of a majority of the directors present at a meeting at which a quorum is present shall be the act of the Board of Directors.

Section 2.6 Committees. The Board of Directors may, by resolution passed by a majority of the whole Board of Directors, designate one or more committees, each committee to consist of one or more directors of the Corporation. The Board of Directors may designate one or more directors as alternate members of any committee, who may replace any absent or disqualified member at any meeting of the committee. In the absence or disqualification of a member of the committee, the member or members present at any meeting and not disqualified from voting, whether or not a quorum, may unanimously appoint another member of the Board of Directors to act at the meeting in place of any such absent or disqualified member. Any such committee, to the extent permitted by law and provided in these By-laws or in the resolution of the Board of Directors designating such committee, or an amendment to such resolution, shall have and may exercise all the powers and authority of the Board of Directors in the management of the business and affairs of the Corporation, and may authorize the seal of the Corporation to be affixed to all papers which may require it.

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Section 2.7 Telephonic Meetings. Directors, or any committee of directors designated by the Board of Directors, may participate in a meeting of the Board of Directors or such committee by means of conference telephone or other communications equipment by means of which all persons participating in the meeting can hear each other, and participation in a meeting pursuant to this Section 2.8 shall constitute presence in person at such meeting.

Section 2.8 Informal Action by Directors. Unless otherwise restricted by the Certificate of Incorporation or these By-laws, any action required or permitted to be taken at any meeting of the Board of Directors, or of any committee thereof, may be taken without a meeting if all members of the Board of Directors or such committee, as the case may be, consent thereto in writing (which may be in counterparts) or by electronic transmission, and the written consent or consents or electronic transmission or transmissions are filed with the minutes of proceedings of the Board of Directors or such committee. Such filing shall be made in paper form if the minutes of the Corporation are maintained in paper form and shall be in electronic form if the minutes are maintained in electronic form.

Section 2.9 Committee Rules. Unless the Board of Directors otherwise provides, each committee designated by the Board of Directors may make, alter and repeal rules for the conduct of its business. In the absence of such rules each committee shall conduct its business in the same manner as the Board of Directors conducts its business pursuant to this Article II of these By-laws.

Section 2.10 Reliance upon Records. Every director, and every member of any committee of the Board of Directors, shall, in the performance of his or her duties, be fully protected in relying in good faith upon the records of the Corporation and upon such information, opinions, reports or statements presented to the Corporation by any of its officers or employees, or committees of the Board of Directors, or by any other person as to matters the director or member reasonably believes are within such other person’s professional or expert competence and who has been selected with reasonable care by or on behalf of the Corporation, including, but not limited to, such records, information, opinions, reports or statements as to the value and amount of the assets, liabilities and/or net profits of the Corporation, or any other facts pertinent to the existence and amount of surplus or other funds from which dividends might properly be declared and paid, or with which the Corporation’s capital stock might properly be purchased or redeemed.

Section 2.11 Interested Directors. A director who is directly or indirectly a party to a contract or transaction with the Corporation, or is a director or officer of or has a financial interest in any other corporation, partnership, association or other organization which is a party to a contract or transaction with the Corporation, may be counted in determining whether a quorum is present at any meeting of the Board of Directors or a committee thereof at which such contract or transaction is considered or authorized, and such director may participate in such meeting and vote on such authorization to the extent permitted by applicable law, including Section 144 of the General Corporation Law of the State of Delaware.

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Section 2.12 Compensation. Unless otherwise restricted by the Certificate of Incorporation, the Board of Directors shall have the authority to fix the compensation of directors. The directors may be paid their reasonable expenses, if any, of attendance at each meeting of the Board of Directors or a committee thereof and may be paid a fixed sum for attendance at each such meeting and an annual retainer or salary for services as a director or committee member. No such payment shall preclude any director from serving the Corporation in any other capacity and receiving compensation therefor.

ARTICLE III

Officers

Section 3.1 Executive Officers; Election; Qualification; Term of Office. The Board of Directors shall elect a President and may, if it so determines, elect a Chairman of the Board from among its members. The Board of Directors shall also elect a Secretary and may elect one or more Vice Presidents, one or more Assistant Secretaries, a Treasurer and one or more Assistant Treasurers. Any number of offices may be held by the same person. Each officer shall hold office until the first meeting of the Board of Directors after the annual meeting of stockholders next succeeding his or her election, and until his or her successor is elected and qualified or until his or her earlier death, resignation or removal.

Section 3.2 Resignation; Removal; Vacancies. Any officer may resign at any time by giving written notice to the Chairman of the Board, if any, the President or the Secretary. Unless otherwise stated in a notice of resignation, it shall take effect when received by the officer to whom it is directed, without any need for its acceptance. The Board of Directors may remove any officer with or without cause at any time, but such removal shall be without prejudice to the contractual rights of such officer, if any, with the Corporation. A vacancy occurring in any office of the Corporation may be filled for the unexpired portion of the term thereof by the Board of Directors at any regular or special meeting.

Section 3.3 Powers and Duties of Executive Officers. The officers of the Corporation shall have such powers and duties in the management of the Corporation as may be prescribed by the Board of Directors and, to the extent not so provided, as generally pertain to their respective offices, subject to the control of the Board of Directors. The Board of Directors may require any officer, agent or employee to give security for the faithful performance of his or her duties.

Section 3.4 Chief Executive Officer. The Chief Executive Officer of the Corporation shall in general supervise and control all of the business affairs of the Corporation, subject to the direction of the Board of Directors, shall be its chief policy-making officer and shall be responsible for implementing all decisions of the Board of Directors. The Chief Executive Officer may execute, in the name and on behalf of the Corporation, any deeds, mortgages, bonds, contracts or other instruments which the Board of Directors or a committee thereof has authorized to be executed, except in cases where the execution shall have been expressly delegated by the Board of Directors or a committee thereof to some other officer or agent of the Corporation.

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Section 3.5 President. The President shall be the Chief Executive Officer if that position is not filled by another individual and shall have the powers and perform the duties incident to that particular position; if the Chief Executive Officer position has been filled by another individual, the President shall assist the Chief Executive Officer in the performance of the duties of the Chief Executive Officer and shall, at the request of the Chief Executive Officer, represent such Chief Executive Officer at public or private functions and ceremonies and perform such other functions as may be reasonably requested by the Chief Executive Officer. The President shall serve as the direct supervisor for the operating departments of the Corporation as determined from time to time by the Board of Directors and the Chief Executive Officer. Subject to the further direction from time to time of the Board of Directors, the President shall have authority to execute any and all documentation on behalf of the Corporation and shall have all of the powers and perform all the duties incident to the position as well as such other duties as may be prescribed by the Board of Directors or as may be prescribed in these By-laws.

Section 3.6 Vice Presidents. The Vice Presidents shall perform such duties as shall be assigned from time to time by the President or as the Board of Directors may from time to time prescribe.

Section 3.7 Secretary. In addition to such other duties, if any, as may be assigned to the Secretary by the Board of Directors, the Chairman of the Board, if any, or the President, the Secretary shall (i) keep the minutes of proceedings of the stockholders, the Board of Directors and any committee of the Board of Directors in one or more books provided for that purpose; (ii) see that all notices are duly given in accordance with the provisions of these By-laws or as required by law; (iii) be the custodian of the records and seal of the Corporation; (iv) affix or cause to be affixed the seal of the Corporation or a facsimile thereof, and attest the seal by his or her signature, to all certificates for shares of stock of the Corporation and to all other documents the execution of which under seal is authorized by the Board of Directors; and (v) unless such duties have been delegated by the Board of Directors to a transfer agent of the Corporation, keep or cause to be kept a register of the name and address of each stockholder, as the same shall be furnished to the Secretary by such stockholder, and have general charge of the stock transfer records of the Corporation.

Section 3.8 Treasurer. The Treasurer shall be the chief financial officer and shall have custody of the corporate funds and securities and shall keep full and accurate accounts of receipts and disbursements in books belonging to the corporation and shall deposit all moneys and other valuable effects in the name and to the credit of the corporation in such depositories as may be designated by authority of the board of directors. The Treasurer shall disburse the funds of the corporation as may be ordered by the Board of Directors, taking proper vouchers for such disbursements, and shall render to the President and the Board of Directors, at its regular meetings, or when the Board of Directors so requires, an account of all transactions as Treasurer and of the financial condition of the Corporation. The Treasurer shall, in general, perform all the duties incident to the office of Treasurer and all such other duties as may be assigned from time to time by the President or the Board of Directors.

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Section 3.9 Chief Medical Officer. The Chief Medical Officer shall assist companies managed by the Corporation with administrative issues relating to policies, procedures and regulatory compliance.

ARTICLE IV

Stock Certificates and Transfers

Section 4.1 Certificate. The shares of stock of the Corporation may be certificated or uncertificated, as provided under the General Corporation Law of the State of Delaware, and shall be entered in the books of the Corporation and registered as they are issued. Any certificates representing shares of stock shall be in such form as the Board may from time to time prescribe, certifying the number and class of shares of the stock owned by the stockholder. Any certificates issued to a stockholder of the Corporation shall be signed by or in the name of the Corporation by the Chairman of the Board, if any, or the President or a Vice President, and by the Secretary or an Assistant Secretary, of the Corporation. Any or all of the signatures on the certificate may be facsimile, stamp or other imprint. In case any officer, transfer agent, or registrar who has signed or whose facsimile, stamp or other imprint signature has been placed upon a certificate shall have ceased to be such officer, transfer agent or registrar before such certificate is issued, it may be issued by the Corporation with the same effect as if such officer, transfer agent, or registrar continued to be such at the date of issue.

Section 4.2 Lost, Stolen or Destroyed Certificates; Issuance of New Certificates. The Corporation may issue a new certificate for stock in the place of any certificate theretofore issued by it, alleged to have been lost, stolen or destroyed, and the Corporation may require the owner of the lost, stolen or destroyed certificate, or such stockholder’s legal representative, to give the Corporation a bond sufficient to indemnify it against any claim that may be made against it on account of the alleged loss, theft or destruction of any such certificate or the issuance of such new certificate.

Section 4.3 Transfers of Stock. Upon surrender to the Corporation or the transfer agent of the Corporation of a certificate for stock of the Corporation duly endorsed or accompanied by proper evidence of succession, assignment or authority to transfer or, if the relevant stock certificate is claimed to have been lost, stolen or destroyed, upon compliance with the provisions of Section 4.2 of these By-laws, and upon payment of applicable taxes with respect to such transfer, and in compliance with any restrictions on transfer applicable to such stock certificate or the shares represented thereby of which the Corporation shall have notice and subject to such rules and regulations as the Board of Directors may from time to time deem advisable concerning the transfer and registration of stock certificates, the Corporation shall issue a new certificate or certificates for such stock to the person entitled thereto, cancel the old certificate and record the transaction upon its books. Transfers of stock shall be made only on the books of the Corporation by the registered holder thereof or by such holder’s attorney or successor duly authorized as evidenced by documents filed with the Secretary or transfer agent of the Corporation. Whenever any transfer of stock shall be made for collateral security, and not absolutely, it shall be so expressed in the entry of transfer if, when the certificate or certificates representing such stock are presented to the Corporation for transfer, both the transferor and transferee request the Corporation to do so.

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Section 4.4 Stockholders of Record. The Corporation shall be entitled to treat the holder of record of any stock of the Corporation as the holder thereof and shall not be bound to recognize any equitable or other claim to or interest in such stock on the part of any other person, whether or not it shall have express or other notice thereof, except as otherwise required by the laws of the State of Delaware.

ARTICLE V

Notices

Section 5.1 Manner of Notice.

(a) Except as otherwise provided by law, the Certificate of Incorporation or these By-laws, whenever notice is required to be given to any stockholder, director or member of any committee of the Board of Directors, such notice may be given by (i) personal delivery, (ii) depositing it, in a sealed envelope, in the United States mails, first class, postage prepaid, addressed, (iii) delivering to a company for overnight or second day mail or delivery, (iv) delivering it to a telegraph company, charges prepaid, for transmission, or by transmitting it via telecopier, or (v) any other reliable means permitted by applicable law (including, subject to Section 5.1(b), electronic transmission) to such stockholder, director or member, either at the address of such stockholder, director or member as it appears on the records of the Corporation or, in the case of such a director or member, at his or her business address; and such notice shall be deemed to be given at the time when it is thus personally delivered, deposited, delivered or transmitted, as the case may be. Such requirement for notice shall also be deemed satisfied, except in the case of stockholder meetings, if actual notice is received orally or by other writing by the person entitled thereto as far in advance of the event with respect to which notice is being given as the minimum notice period required by law or these By-laws.

(b) Without limiting the foregoing, any notice to stockholders given by the Corporation pursuant to these By-laws shall be effective if given by a form of electronic transmission consented to by the stockholder to whom the notice is given. Any such consent shall be revocable by the stockholder by written notice to the Corporation and shall also be deemed revoked if (1) the Corporation is unable to deliver by electronic transmission two consecutive notices given by the Corporation in accordance with such consent and (2) such inability becomes known to the Secretary of the Corporation, the transfer agent or other person responsible for the giving of notice; provided, however, that the inadvertent failure to treat such inability as a revocation shall not invalidate any meeting or other action. Notice given by a form of electronic transmission in accordance with these By-laws shall be deemed given: (i) if by facsimile telecommunication, when directed to a number at which the stockholder has consented to receive notice; (ii) if by electronic mail, when directed to an electronic mail address at which the stockholder has consented to receive notice; (iii) if by a posting on an electronic network, together with separate notice to the stockholder of such specific posting, upon the later of such posting and the giving of such separate notice; and (iv) if by another form of electronic transmission, when directed to the stockholder.

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Section 5.2 Dispensation with Notice.

(a) Whenever notice is required to be given by law, the Certificate of Incorporation or these By-laws to any stockholder to whom (i) notice of two consecutive annual meetings of stockholders, or (ii) all, and at least two, payments (if sent by first class mail) of dividends or interest on securities of the Corporation during a 12-month period, have been mailed addressed to such stockholder at the address of such stockholder as shown on the records of the Corporation and have been returned undeliverable, the giving of such notice to such stockholder shall not be required. Any action or meeting which shall be taken or held without notice to such stockholder shall have the same force and effect as if such notice had been duly given. If any such stockholder shall deliver to the Corporation a written notice setting forth the then current address of such stockholder, the requirement that notice be given to such stockholder shall be reinstated.

(b) Whenever notice is required to be given by law, the Certificate of Incorporation or these By-laws to any person with whom communication is unlawful, the giving of such notice to such person shall not be required, and there shall be no duty to apply to any governmental authority or agency for a license or permit to give such notice to such person. Any action or meeting which shall be taken or held without notice to any such person with whom communication is unlawful shall have the same force and effect as if such notice had been duly given.

Section 5.3 Waiver of Notice. Any written waiver of notice, signed by the person entitled to notice, whether before or after the time stated therein, shall be deemed equivalent to notice. Attendance of a person at a meeting shall constitute a waiver of notice of such meeting, except when the person attends a meeting for the express purpose of objecting, at the beginning of the meeting, to the transaction of any business because the meeting is not lawfully called or convened. Neither the business to be transacted at, nor the purpose of, any regular or special meeting of the stockholders, directors, or members of a committee or directors need be specified in any written waiver of notice.

ARTICLE VI

General

Section 6.1 Fiscal year. The fiscal year of the Corporation shall be determined by resolution of the Board of Directors. Absent any contrary resolution, the fiscal year shall be the calendar year.

Section 6.2 Seal. The corporate seal shall have the name of the Corporation inscribed thereon and shall be in such form as may be approved from time to time by the Board of Directors.

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Section 6.3 Form of Records. Any records maintained by the Corporation in the regular course of its business, including its stock ledger, books of account, and minute books, may be kept on, or be in the form of, punch cards, magnetic tape, photographs, microphotographs, electronic format or any other information storage device, provided that the records so kept can be converted into clearly legible form within a reasonable time. The Corporation shall so convert any records so kept upon the request of any person entitled to inspect the same.

Section 6.4 Definitions.

(a) For purposes of these By-laws, “electronic transmission” means any form of communication, not directly involving the physical transmission of paper, that creates a record that may be retained, retrieved and reviewed by a recipient thereof, and that may be directly reproduced in paper form by such a recipient through an automated process.

(b) For purposes of these By-laws, “public disclosure” shall mean disclosure in a press release reported by the Dow Jones News Service, Associated Press or comparable national news service, or in a document publicly filed by the Corporation with the Securities and Exchange Commission pursuant to Section 13, 14 or 15(d) of the Exchange Act.

Section 6.5 Amendment of By-laws. These By-laws may be altered or repealed, and new By-laws made, by the majority vote of the whole Board of Directors, provided, however, a By-law adopted by the holders of stock representing a majority of the votes which could be cast by the holders of all outstanding stock that prescribes the required vote for the election of directors may not be altered by the Board of Directors. The holders of stock having representing a majority of the votes which could be cast by the holders of all outstanding stock may make additional By-laws and may alter and repeal any By-laws whether adopted by them or otherwise.

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