Exhibit 99.1

Contact:

David Myers, Vice President, Investor Relations

(314) 810-3115

investor.relations@express-scripts.com

Express Scripts Reports Second Quarter 2013 Results

Increases 2013 Earnings Guidance

ST. LOUIS, July 29, 2013 — Express Scripts Holding Company (Nasdaq: ESRX) announced 2013 second quarter net income from continuing operations attributable to Express Scripts shareholders of $558.3 million, or $0.67 per diluted share. Adjusted earnings per diluted share from continuing operations attributable to Express Scripts, as detailed in Table 4, were $1.12 for the second quarter.

“Our second quarter results reflect the successful execution of our business model of alignment,” stated George Paz, chairman and chief executive officer. “As we head toward 2014 and the introduction of insurance exchanges, additional costly regulations, escalation of brand drug prices and increased specialty drug utilization, our clients face unprecedented challenges to manage the cost and complexity of the pharmacy benefit. Our clinical specialization, advanced application of the behavioral sciences, and ability to leverage actionable data allow us to drive down costs, reduce waste and improve health in ways no other company can.”

Second Quarter 2013 Review

2013 Guidance

As expected, earnings for a large client were realized in the second quarter due to the structure of the contract. The Company anticipates this pattern of earnings to continue for the foreseeable future. Adjusted earnings per diluted share from continuing operations attributable to Express Scripts for the third quarter are expected to be between $1.05 and $1.09.

The Company previously provided 2013 guidance on adjusted earnings per diluted share from continuing operations attributable to Express Scripts in the range of $4.23 to $4.33, or growth of 13% to 16% over 2012. The Company now anticipates achieving adjusted earnings per diluted share from continuing operations attributable to Express Scripts for 2013 in the range of $4.26 to $4.34, or 14% to 16% growth over 2012. Adjusted earnings per diluted share from continuing operations attributable to Express Scripts for 2013 exclude items as detailed in Table 6.

Chief Financial Officer Transition Plan

The Company announced that it is initiating a Chief Financial Officer transition process. As part of that transition, Jeff Hall will no longer serve in the role of Executive Vice President and Chief Financial Officer of the Company, effective as of July 30, 2013. Mr. Hall will continue his employment with the Company in a different role through September 1, 2013 in order to facilitate a smooth and orderly transition. The Company has commenced a search for a permanent successor as Chief Financial Officer and will make an announcement once a successor is appointed.

Express Scripts also announced that effective July 30, 2013, Matthew Harper will serve as the Company’s interim Chief Financial Officer until such time as the Board has appointed a permanent successor to Mr. Hall. Mr. Harper, 44, joined the Company in 2000 and has served as Vice President over financial planning and analysis since April 2013. Previously, Mr. Harper served in a variety of roles with the Company, including Vice President over treasury operations from 2004 until April 2013. Mr. Harper will continue in his current role as a Vice President of the Company while serving as interim Chief Financial Officer.

About Express Scripts

Express Scripts (NASDAQ: ESRX) manages more than a billion prescriptions each year for tens of millions of patients. On behalf of our clients – employers, health plans, unions and government health programs – we make the use of prescription drugs safer and more affordable. Express Scripts uniquely combines three capabilities – behavioral sciences, clinical specialization and actionable data – to create Health Decision Science^SM, our innovative approach to help individuals make the best drug choices, pharmacy choices and health choices. Better decisions mean healthier outcomes.

Headquartered in St. Louis, Express Scripts provides integrated pharmacy benefit management services, including network-pharmacy claims processing, home delivery, specialty benefit management, benefit-design consultation, drug-utilization review, formulary management, and medical and drug data analysis services. The company also distributes a full range of biopharmaceutical products and provides extensive cost-management and patient-care services.

For more information, visit Lab.Express-Scripts.com or follow @ExpressScripts on Twitter.

SAFE HARBOR STATEMENT

This press release contains forward-looking statements, including, but not limited to, our 2013 guidance and our statements related to the Company’s plans, objectives, expectations (financial and otherwise) or intentions. Actual results may differ significantly from those projected or suggested in any forward-looking statements. Factors that may impact these forward-looking statements can be found in the Management’s Discussion and Analysis of Financial Condition and Results of Operations in the Company’s Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission (“SEC”) on or about July 29, 2013 and Item 1A – “Risk Factors” in the Company’s Annual Report on Form 10-K filed with the SEC on February 19, 2013. A copy of these documents can be found at the Investor Information section of Express Scripts’ web site at http://www.express-scripts.com/corporate.

We do not undertake any obligation to release publicly any revisions to such forward-looking statements to reflect events or circumstances after the date hereof or to reflect the occurrence of unanticipated events.

EXPRESS SCRIPTS HOLDING COMPANY

Unaudited Consolidated Statement of Operations

EXPRESS SCRIPTS HOLDING COMPANY

Unaudited Consolidated Balance Sheet

EXPRESS SCRIPTS HOLDING COMPANY

Unaudited Consolidated Statement of Cash Flows

Table 1

Express Scripts Holding Company Unaudited Consolidated Selected Information

(in millions)

Note: See Appendix for Footnotes

Table 2

Calculation of Express Scripts Holding Company Adjusted Gross Profit and SG&A—Continuing Operations

(in millions)

Note: See Appendix for Footnotes

The Company is providing adjusted gross profit and adjusted selling, general and administrative expenses (both of which are non-GAAP financial measures), in each case, excluding the impact of non-recurring charges and amortization of intangible assets in order to compare the underlying financial performance to prior periods.

Table 3

Express Scripts Holding Company EBITDA and Adjusted EBITDA Reconciliation

(in millions, except per claim data)

The following is a reconciliation of net income from continuing operations attributable to Express Scripts to EBITDA and adjusted EBITDA from continuing operations attributable to Express Scripts, and adjusted EBITDA from continuing operations attributable to Express Scripts per adjusted claim. The Company believes net income is the most directly comparable measure calculated under U.S. GAAP.

Note: See Appendix for Footnotes

The Company is providing EBITDA and adjusted EBITDA excluding the impact of non-recurring charges (both of which are non-GAAP financial measures) in order to compare the underlying financial performance to prior periods.

EBITDA from continuing operations attributable to Express Scripts is earnings before other income (expense), interest, taxes, depreciation and amortization, or alternatively calculated as operating income from continuing operations plus depreciation and amortization less non-controlling interest. EBITDA from continuing operations attributable to Express Scripts is presented because it is a widely accepted indicator of a company’s ability to service indebtedness and is frequently used to evaluate a company’s performance. EBITDA from continuing operations attributable to Express Scripts, however, should not be considered as an alternative to net income from continuing operations, as a measure of operating performance, as an alternative to cash flow, as a measure of liquidity or as a substitute for any other measure computed in accordance with accounting principles generally accepted in the United States. In addition, our definition and calculation of EBITDA from continuing operations attributable to Express Scripts may not be comparable to that used by other companies.

Adjusted EBITDA from continuing operations attributable to Express Scripts per adjusted claim is a supplemental measurement used by analysts and investors to help evaluate overall operating performance. We have calculated adjusted EBITDA from continuing operations attributable to Express Scripts excluding certain charges recorded each year, as these charges are not considered an indicator of ongoing company performance. Adjusted EBITDA from continuing operations attributable to Express Scripts per adjusted claim is calculated by dividing adjusted EBITDA from continuing operations attributable to Express Scripts by the adjusted claim volume for the period. This measure is used as an indicator of adjusted EBITDA attributable to Express Scripts performance on a per-unit basis. Adjusted EBITDA from continuing operations attributable to Express Scripts, and as a result, adjusted EBITDA from continuing operations attributable to Express Scripts per adjusted claim, are each affected by the changes in claim volumes between retail and home delivery, the relative representation of brand-name, generic and specialty pharmacy drugs, as well as the level of efficiency in the business.

Table 4

Calculation of Express Scripts Holding Company Adjusted EPS

Note: See Appendix for Footnotes

The Company is providing EPS and EPS excluding the impact of non-recurring items and amortization of intangible assets (which is a non-GAAP financial measure) in order to compare the underlying financial performance to prior periods.

Table 5

Calculation of Express Scripts Holding Company Adjusted Effective Income Tax Rate for Continuing Operations

(in millions)

Note: See Appendix for Footnotes.

The Company is providing adjusted effective income tax rate for continuing operations attributable to Express Scripts excluding the impact of non-recurring items and amortization of intangible assets (which is a non-GAAP financial measure) in order to compare the underlying financial performance to prior periods.

Table 6

Express Scripts Holding Company 2013 Guidance Information

The full-year impact of transaction, integration and other non-recurring costs have yet to be determined. Accordingly, the Company is unable to include these charges in the list of GAAP items not included in guidance for 2013 revised adjusted EPS from continuing operations or to provide a reconciliation to the corresponding GAAP measure.

Note: See Appendix for Footnotes

Appendix

Footnotes

Amortization of legacy Express Scripts intangible assets include amounts in both revenues and selling, general and administrative expense.

Revenue amortization is related to the customer contract with WellPoint which consummated upon closing of the NextRx acquisition in 2009. Under U.S. GAAP standards, amortization of intangibles that arise in connection with consideration given to a customer by a vendor is characterized as a reduction of revenues. Intangible amortization of $28.5 million ($17.3 million and $16.5 million net of tax in 2013 and 2012, respectively) is included as a reduction to revenue for the three months ended June 30, 2013 and 2012. Intangible amortization of $57.0 million ($34.6 million and $34.5 million net of tax in 2013 and 2012, respectively) is included as a reduction to revenue for the six months ended June 30, 2013 and 2012.

Other legacy Express Scripts intangible amortization of $10.2 million ($6.2 million and $5.9 million net of tax in 2013 and 2012, respectively) is included in selling, general and administrative expense for the three months ended June 30, 2013 and 2012, respectively. Other legacy Express Scripts intangible amortization of $20.3 million ($12.3 million net of tax) and $20.4 million ($12.4 million net of tax) is included in selling, general and administrative expense for the six months ended June 30, 2013 and 2012, respectively.

Amortization of intangible assets related to the acquisition of Medco Health Solutions, Inc. (“Medco”) of $466.9 million ($283.4 million net of tax) and $473.4 million ($274.2 million net of tax) for the three months ended June 30, 2013 and 2012, respectively, is included in selling, general and administrative expense. Amortization of intangible assets related to the acquisition of Medco of $929.7 million ($564.3 million net of tax) and $473.4 million ($287.0 million net of tax) for the six months ended June 30, 2013 and 2012, respectively, is included in selling, general and administrative expense.

Costs of $36.6 million ($22.2 million net of tax) and $11.9 million ($6.9 million net of tax) primarily composed of integration-related activities, are included in cost of revenues for the three months ended June 30, 2013 and 2012, respectively. Costs of $81.1 million ($49.2 million net of tax) and $11.9 million ($7.2 million net of tax) primarily composed of integration-related activities, are included in cost of revenues for the six months ended June 30, 2013 and 2012, respectively.

Costs of $105.3 million ($63.9 million net of tax) and $380.3 million ($220.4 million net of tax) primarily composed of professional fees, integration-related activities and severance costs, including stock compensation, are included in selling, general and administrative expense in the three months ended June 30, 2013 and 2012, respectively. Costs of $218.9 million ($132.8 million net of tax) and $407.0 million ($245.8 million net of tax) primarily composed of professional fees, integration-related activities and severance costs, including stock compensation, are included in selling, general and administrative expense in the six months ended June 30, 2013 and 2012, respectively.

The Company recorded a net benefit of $3.5 million ($2.1 million net of tax) within selling, general and administrative expenses for the six months ended June 30, 2013 in conjunction with a final settlement related to the strategic decision to exit various businesses.

Net income from discontinued operations includes charges related to European operations of $16.0 million, amortization of intangible assets related to the acquisition of Medco of $15.5 million, and $1.7 million discrete tax charges, offset by a gain recognized on the disposal of portions of the UBC business of $18.3 million for the six months ended June 30, 2013. Net income from discontinued operations, net of tax includes amounts relating to these items totaling $9.7 million net of tax for the six months ended June 30, 2013.

Net income from discontinued operations includes amortization of intangible assets related to the acquisition of Medco of $8.5 million for the three months and six months ended June 30, 2012. Net income from discontinued operations, net of tax includes amounts relating to this item, totaling $4.9 million net of tax for the three months and six months ended June 30, 2012.