Certara, Inc.

The following table illustrates the activities of equity security repurchases during the three months ended at September 30, 2025.

a. On April 11, 2025, our Board of Directors approved a stock repurchase program authorizing the Company to repurchase up to $100 million of its common stock. Under this program, the Company may repurchase shares from time to time, depending on market conditions and alternate uses of capital. The timing and actual number of shares repurchased will depend on a variety of factors, including price, general business and market conditions and alternate uses of capital. The share repurchase program may be effected through Rule 10b5-1 plans, open market purchases, each in compliance with Rule 10b-18 under the Exchange Act, or privately negotiated transactions. The program may be suspended or discontinued at any time and does not have an expiration date. During the three months ended September 30, 2025, the Company repurchased 1,230,398 shares of its common stock at an average price of $11.09 per share, as part of the stock repurchase program authorized on April 11, 2025.

b. The Company’s net share repurchases are subject to a 1% excise tax under the Inflation Reduction Act. This excise tax is included in the cost of shares repurchased, as reflected in the condense consolidated statement of stockholders’ equity. The repurchases above do not include the excise tax.

c. Also includes shares purchased by the Company from employees for the payment of taxes resulting from issuance of common stock upon the vesting of RSUs relating to stock-based compensation plans. Employees tendered 5,266 shares in the third quarter of 2025.