X0306 4 2019-02-28 0 0000749251 GARTNER INC IT 0001198849 HALL EUGENE A 56 TOP GALLANT ROAD P.O. BOX 10212 STAMFORD CT 06904-2212 1 1 0 0 CEO Common Stock 2019-02-28 4 S 0 59727 142.90 D 1174006 D Common Stock 2019-02-28 4 J 0 43 135.19 A 1233733 D Common Stock 2019-03-01 4 S 0 31208 143.83 D 1142798 D This transaction was executed in multiple trades at prices ranging from $142.32 to $143.62. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected. Represents shares acquired under Gartner Inc.'s 2011 Employee Stock Purchase Plan in a transaction exempt from Section 16(b) pursuant to Rule 16b-3(c). This transaction was executed in multiple trades at prices ranging from $143.01 to $144.73. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected. /s/ Kevin Tang for Eugene A. Hall 2019-03-04