X0306 4 2020-12-16 0 0001192448 GLAUKOS Corp GKOS 0001705850 Gilliam Joseph E C/O GLAUKOS CORPORATION, 229 AVENIDA FABRICANT SAN CLEMENTE CA 92672 0 1 0 0 CFO, SVP Corporate Development Common Stock 2020-12-16 4 A 0 3182 71.94 A 43707 D Represents shares of common stock subject to a performance-based restricted stock unit award previously granted by the Issuer on March 14, 2019, the vesting of which was subject to the Issuer's achievement of certain performance goals within three years of the grant date. The Compensation Committee of the Issuer's Board of Directors determined on December 16, 2020 that the performance goals had been achieved. The number of shares of common stock reported consists of the 6,311 shares underlying the restricted stock units originally granted less 3,129 shares withheld by the Issuer with respect to income taxes payable by the Reporting Person upon the vesting and delivery of the shares of common stock underlying these restricted stock units. The number of common stock reported also includes 459 shares that were acquired by the Reporting Person in July 2020 pursuant to the Issuer's Employee Stock Purchase Plan. Includes 20,056 restricted stock units that have not yet vested or been delivered to the Reporting Person. /s/ Diana Scherer, Attorney-in-Fact 2020-12-18