Yes — for clients who have Medicare, Medicare must be billed as the primary payer before Medicaid for therapy services (OT, PT, ST) provided at ADDT programs. This is a fundamental Medicaid requirement: Medicaid is always the payer of last resort.

Medicare Part B covers outpatient therapy services. If a client is Medicare-eligible and you provide therapy, you must:
1. Be enrolled as a Medicare provider (have a Medicare NPI/provider number).
2. Submit therapy claims to Medicare first.
3. Bill Medicaid/PASSE for any remaining cost-sharing up to the Medicaid rate after Medicare pays.

Providers who are not enrolled with Medicare cannot bill Medicare and, as a result, generally cannot bill Medicaid for therapy services provided to Medicare-eligible clients. ADDT programs providing therapy to Medicare-eligible clients should prioritize Medicare enrollment if they have not already done so.