X0306 4 2019-12-16 0001102934 CABOT MICROELECTRONICS CORP CCMP 0001752950 Thorp Eleanor Kate 870 N COMMONS DRIVE AURORA IL 60504 1 VP, Human Resources Common Stock 2019-12-16 4 A 0 218 137.18 A 2643.614 D Common Stock 2019-12-16 4 A 0 109 137.18 A 2752.614 D Represents restricted shares purchased under the Issuer's Omnibus Incentive Plan pursuant to the Issuer's Deposit Share Program: 218 of such shares are Deposit Shares under the Program purchased at full value by the Participant that vested on 12/16/2019, and 109 shares of such are Award Shares under the Program awarded to the Participant that will vest on 12/16/2022, subject to the satisfaction of certain conditions. /s/ H. Carol Bernstein (Power of Attorney) 2019-12-17