X0306 4 2021-12-31 0 0001101680 DZS INC. DZSI 0001599956 Bross Matthew W C/O DZS INC. 5700 TENNYSON PARKWAY, 4TH FLOOR PLANO TX 75024 1 0 0 0 Common Stock 2021-12-31 4 M 0 1071 0.00 A 4275 D Restricted Stock Units 2021-12-31 4 M 0 1071 D Common Stock 1071 0 D Restricted Stock Units 2022-01-03 4 M 0 3889 A Common Stock 3889 3889 D This represents the fourth vesting on December 31, 2021 in the amount of 1,071 units for a total amount vested of 4,275 of the restricted stock units issued on January 4, 2021. Each restricted stock unit represents the right to receive one share of the issuer's common stock upon vesting. Represents restricted stock units issued to the reporting person that will vest in four equal installments on March 31, 2022, June 30, 2022, September 30, 2022 and December 31, 2022, subject to the reporting person's continued service to the issuer on each such vesting date. Each restricted stock unit represents the right to receive one share of the company's common stock upon vesting. /s/Laura Larsen-Misunas as Power of Attorney 2022-01-04