Excluding employees from eligibilty in plan provisions for small PSP

[Lori H]

a small PSP has eligibility requirements of age 20.5 and 6 months of service. They would like to amend to exclude employees who do not work full time. I do not think this is an option. They could bump up to year of service age 21, perhaps even 2 years of service since the plan vesting is already 100%, but if employees work appx 20 hours a week, they will be eligible to be in the plan, correct?

[QDROphile]

Other than the year of service requirement, an employee cannot be excluded based on service (or lack of service). See IRC section 410(a). Year of service for eligibility is based on 1000 hours of service. Make sure you understand the conventions for counting service if actual hours are not recorded.