Amends GS 135-4 and GS 128-26 concerning omitted membership service under the Teachers' and State Employees' Retirement System and the Local Government Employees' Retirement System. Adds identical provisions to each statute to require an employer to provide written notification of the total hours an employee worked in the preceding 12 months upon request from the employee classified as part-time. Requires the employer to provide a copy of the notification to the Retirement Systems Division upon request. Requires an employer to pay the applicable employer contributions if an employee is found to have been classified as part-time in error and was not eligible to earn membership service due to that error so long as the employee has paid a lump sum equal to the applicable employee contributions within one year of the omission. Effective January 1, 2021, and applies to the purchase of service for work performed on or after January 1, 2020.