X0306 4 2019-01-15 0 0001490892 CoreSite Realty Corp COR 0001423891 Thompson John David C/O CORESITE REALTY CORPORATION 1001 17TH STREET, SUITE 500 DENVER CO 80202 1 0 0 0 Restricted Stock Units 2019-01-15 4 A 0 144 0.00 A Common Stock 144 12360 D Each Restricted Stock Unit ("RSU") represents the right to receive one share of common stock of the issuer. The reporting person also holds a tandem Dividend Equivalent for each RSU held, which gives the reporting person the right to receive, upon the payment of any ordinary quarterly cash dividend paid to holders of common stock of the issuer, an equivalent payment in the form of additional RSUs based on the fair market value of the issuer's common stock on the date of payment. One hundred twenty-nine (129) RSUs vest immediately with the remaining RSUs vesting on May 23, 2019. Pursuant to a deferral election made by the reporting person, vested RSUs are payable upon the earliest of (a) the reporting person's separation from service with the issuer, (b) the reporting person's death or (c) the date of a change in control of the issuer. The RSUs have no expiration date. /s/ Derek S. McCandless, Attorney-in-Fact 2019-01-17