X0306 4 2020-04-07 0001005284 UNIVERSAL DISPLAY CORP \PA\ OLED 0001423446 Mahon Janice K C/O UNIVERSAL DISPLAY CORPORATION 375 PHILLIPS BLVD. EWING NJ 08618 0 1 0 0 VP of Tech Commercialization Common Stock 2020-04-07 4 A 0 1184 0 A 38202 D Common Stock 2020-04-07 4 F 0 605 134.75 D 37597 D These shares were granted to Ms. Mahon as performance units under the Company's Long Term Incentive Plan as part of her 2017 compensation and vested subject to the satisfaction of certain performance conditions, which our Compensation Committee certified on April 7, 2020 as having occurred. Includes 24 shares acquired under the Universal Display Corporation Employee Stock Purchase Plan on March 31, 2020. These shares were withheld to satisfy a tax liability in connection with the vesting on April 7, 2020 of 1,184 shares of restricted stock previously granted to Ms. Mahon. /s/ Janice K. Mahon (by Mauro Premutico as power of attorney) 2020-04-09