Form 8973
Form 8973 is the IRS form a certified PEO files to report the start or end of a service contract with a customer, anchoring CPEO tax treatment to specific dates.
The CPEO program’s liability shift is contract-specific: it applies while a qualifying CPEO contract is in effect for identified worksite employees. Form 8973 tells the IRS when that relationship begins and ends, which makes it the paper trail behind the protection a CPEO sells.
Ask for a copy of the Form 8973 filed for your company when you start, and confirm one is filed when you leave. The end-of-relationship filing records when CPEO liability stops and the customer's responsibility resumes.