Exhibit 99.1

THE ADVISORY BOARD COMPANY REPORTS RESULTS FOR

QUARTER ENDED SEPTEMBER 30, 2015

Company Reports Revenue Growth of 39%, Contract Value Growth of 35%, and Announces $100M Increase to Share Repurchase Program

WASHINGTON, D.C. — (November 5, 2015) — The Advisory Board Company (NASDAQ: ABCO), a global technology, research, and services company providing the leading cloud-based comprehensive performance platform for the health care and higher education industries, today announced financial results for the quarter ended September 30, 2015.

Highlights from the third quarter of 2015 are as follows (all comparisons, unless otherwise noted, are to the quarter ended September 30, 2014):

Robert Musslewhite, Chairman and Chief Executive Officer of The Advisory Board Company, commented, “We are pleased with our performance for the quarter and the value we are delivering to our members as they face ongoing change and complexity in their markets. Our results reflect the powerful attributes of our business very clearly, with the combination of rapid top line growth along with even faster EBITDA growth, expanding margins, and solid cash generation. A keen focus on execution across the quarter allowed us to produce excellent operating outcomes, and we are well on pace to end the year with momentum and deliver key financial metrics within the guidance range we provided back in February.”

Mr. Musslewhite continued, “Across these final two months of the year we are heavily focused on continuing to drive outstanding member impact and flawless execution in order to finish the important December quarter strong and to put ourselves in the best possible position for 2016 and beyond.”

Third Quarter Financial Review

Revenue increased 39% to $200.2 million in the quarter ended September 30, 2015, up from $144.2 million for the quarter ended September 30, 2014. Contract value increased 35% to $760.3 million as of September 30, 2015, up from $561.6 million as of September 30, 2014.

Net income attributable to common stockholders was $1.9 million, or $0.04 per diluted share, for the quarter ended September 30, 2015, compared to net income attributable to common stockholders of $6.5 million, or $0.18 per diluted share, for the quarter ended September 30, 2014. Adjusted net income was $14.1 million for the quarter ended September 30, 2015, compared to $15.9 million for the quarter ended September 30, 2014. Non-GAAP earnings per diluted share was $0.33 for the quarter ended September 30, 2015, compared to $0.43 for the quarter ended September 30, 2014.

Adjusted EBITDA increased 71% to $43.4 million for the quarter ended September 30, 2015, up from $25.4 million for the quarter ended September 30, 2014.

Adjusted revenue, adjusted net income, non-GAAP earnings per diluted share, and adjusted EBITDA are non-GAAP financial measures.

Year-to-Date Financial Review

Revenue increased 33% to $564.7 million for the nine month period ended September 30, 2015, up from $424.0 million for the nine month period ended September 30, 2014. Adjusted revenue, which adjusts for the effect on revenue of fair value adjustments to acquired deferred revenue, increased 36% to $577.2 million for the nine month period ended September 30, 2015, up from $424.0 million for the nine month period ended September 30, 2014. Net loss attributable to common stockholders was $13.1 million, or $0.31 per diluted share, for the nine month period ended September 30, 2015, compared to net income attributable to common stockholders of $11.6 million, or $0.31 per diluted share, for the nine month period ended September 30, 2014. Adjusted EBITDA was $129.9 million for the nine month period ended September 30, 2015, up from $75.4 million for the nine month period ended September 30, 2014. Adjusted net income was $44.3 million for the nine month period ended September 30, 2015, up from $39.5 million for the nine month period ended September 30, 2014. Non-GAAP earnings per diluted share was $1.04 for the nine month period ended September 30, 2015, compared to $1.07 for the nine month period ended September 30, 2014.

Share Repurchase Authorization Increased by $100 Million

During the three months ended September 30, 2015, the Company repurchased approximately 678,000 shares of its common stock at a total cost of $33.0 million. Since 2004, the Company has repurchased approximately 17.4 million shares of its common stock at a total cost of $431.8 million.

The Company also announced that its Board of Directors authorized an increase in its share repurchase program of up to an additional $100 million of the Company’s common stock, bringing the total amount authorized to be spent under the program to $550 million. Repurchases will continue to be made from time to time in the open market or in private transactions. The repurchase program does not obligate the Company to repurchase any specific number of shares and may be modified or discontinued at any time. The Company will fund its share repurchases with cash on hand and cash generated from operations.

Outlook for Calendar Year 2015

The Company is reaffirming its annual financial guidance. For calendar year 2015, the Company continues to expect:

Conference Call Information

As previously announced, the Company will hold a conference call to discuss its third quarter performance this evening, November 5, 2015, at 5:30 p.m. Eastern Time. The conference call will be available via live webcast on the Company’s website at www.advisory.com/IR. To participate by telephone, the dial-in number is 888.336.7150.

Participants are advised to dial in at least five minutes prior to the call to register. The webcast will be archived for seven days from 8:00 p.m. Eastern Time on Thursday, November 5, 2015, until 11:00 p.m. Eastern Time on Thursday, November 12, 2015. The Company invites all interested parties to attend the conference call, including the lenders under the Company’s senior secured credit facilities.

A supplemental presentation of information complementary to the information presented in this release and that will be discussed on the conference call will be made available on the Company’s website at www.advisory.com/IR prior to the conference call and will be archived for the same duration as the webcast.

About the Advisory Board Company

The Advisory Board Company is the leading provider of insight-driven technology, research, and services for organizations in transforming industries. Through its innovative membership model, the Company collaborates with more than 230,000 leaders at 5,200 member organizations to elevate performance and solve their most pressing problems. The Company provides strategic guidance, actionable insights, cloud-based software solutions, and comprehensive implementation and management services. For more information, visit www.advisory.com.

Non-GAAP Financial Measures

This news release presents information about the Company’s adjusted revenue, adjusted net income, non-GAAP earnings per diluted share, adjusted EBITDA, adjusted effective tax rate, and adjusted weighted average common shares outstanding-diluted, which are non-GAAP financial measures provided as a complement to the results provided in accordance with accounting principles generally accepted in the United States of America (“GAAP”). A reconciliation of each of the foregoing historical non-GAAP financial measures to the most directly comparable historical GAAP financial measures is provided in the accompanying tables found at the end of this release for each of the fiscal periods indicated.

Caution Regarding Forward-Looking Statements

Statements in this news release that relate to future results and events are forward-looking statements and are based on the Company’s expectations as of the date of this news release. In some cases, you can identify these statements by such forward-looking words as “anticipate,” “believe,” “estimate,” “expect,” “guidance,” “intend,” “may,” “outlook,” “plan,” “potential,” “should,” “will,” “would,” or similar words or expressions. Forward-looking statements in this news release include the Company’s expectations regarding its performance and results for fiscal 2015 with respect to adjusted revenue, adjusted EBITDA, non-GAAP earnings per diluted share, and adjusted effective tax rate.

Actual results and events in future periods may differ materially from those expressed or implied by these forward-looking statements because of a number of risks, uncertainties, and other factors, including those relating to: factors that adversely affect the financial condition of the health care and higher education industries; federal and state law and regulations governing the health care and higher education industries and our members’ and our respective compliance with those applicable laws and regulations; the Company’s ability to sustain high renewal rates on its memberships; maintenance of the Company’s reputation and expansion of its name recognition; the Company’s ability to offer new and valuable products and services; effects of competition; the Company’s ability to maintain a highly-skilled workforce; unsuccessful design or implementation of software or delivery of consulting and management services; delays in generating revenue; effects of federal and state privacy and security laws and cyber attacks and other data security breaches; compliance with federal regulations governing electronic transactions; service disruptions and operational or security failures; ability to collect and maintain member and third party data and to obtain proper permissions and waivers for use and disclosure of information received from members or on their behalf; liability for failure to provide accurate information or for deficient submissions to third-party payors; compliance with federal and state laws governing healthcare fraud and abuse or reimbursement; maintenance of third-party providers and strategic alliances and entry into new alliances; licensing and integration of third-party technologies and data; protection of the Company’s intellectual property; claims of infringement, misappropriation, or violation of proprietary rights of third parties; limitations associated with use of open source technology; changes to estimates and assumptions used to prepare the Company’s consolidated financial statements; any significant increase in bad debt in excess of recorded estimates; failure to realize the anticipated

benefits of the Royall acquisition; diversion of management’s attention from operations by activities focused on the integration of Royall’s business; business and financial risk associated with the pursuit of acquisition opportunities; delays in the delivery by Evolent Health to the Company of its financial statements; any significant impairment of the Company’s goodwill; the Company’s ability to realize a return on its strategic investments; the level of the Company’s debt service obligations and restrictions on its operations under debt covenants; potential imposition of sales and use taxes on sales of the Company’s services; the Company’s ability to realize fully its deferred tax assets; inherent limitations in, and the potential impact of any failure to maintain, effective internal control over financial reporting; effects of issuance of additional capital stock; and provisions in the Company’s charter and bylaws that could discourage takeover attempts.

This list of risks, uncertainties, and other factors is not complete. The Company discusses some of these matters more fully, as well as certain risk factors that could affect the Company’s business, financial condition, results of operations, and prospects, in its filings with the Securities and Exchange Commission, including the Company’s annual report on form 10-KT for the transition period ended December 31, 2014 and its quarterly reports on Form 10-Q and current reports on Form 8-K. These filings are available for review through the Securities and Exchange Commission’s website at www.sec.gov. Any or all forward-looking statements the Company makes may turn out to be wrong, and can be affected by inaccurate assumptions the Company might make or by known or unknown risks, uncertainties, and other factors, including those identified in this news release. Accordingly, you should not place undue reliance on the forward-looking statements made in this news release, which speak only as of its date. The Company does not undertake to update any of its forward-looking statements, whether as a result of circumstances or events that arise after the date they are made, new information, or otherwise.

###

Reconciliation of Non-GAAP Financial Measures

This news release presents information about the Company’s adjusted revenue, adjusted EBITDA, adjusted net income, non-GAAP earnings per diluted share, adjusted effective tax rate, and adjusted weighted average common shares outstanding-diluted, which are non-GAAP financial measures provided as a complement to the results provided in accordance with GAAP.

A reconciliation of each of the foregoing historical non-GAAP financial measures to the most directly comparable historical GAAP financial measures is provided below for each of the fiscal periods indicated. It is not practicable to provide a reconciliation of forecasted adjusted revenue, adjusted EBITDA, adjusted net income, non-GAAP earnings per diluted share, or adjusted effective tax rate to the most directly comparable GAAP financial measures because certain items required for the forecast of such GAAP financial measures, including fair value adjustments to acquisition-related earn-out liabilities, equity in income (loss) of unconsolidated entity, and gains and losses on investment in common stock warrants, cannot reasonably be estimated or predicted at this time.

THE ADVISORY BOARD COMPANY

UNAUDITED CONSOLIDATED STATEMENTS OF INCOME

AND OTHER OPERATING STATISTICS

(In thousands, except per share data)

THE ADVISORY BOARD COMPANY

CONSOLIDATED BALANCE SHEETS

(In thousands)

THE ADVISORY BOARD COMPANY

UNAUDITED CONSOLIDATED STATEMENTS OF CASH FLOWS

(In thousands)