Medicare Secondary Payer (MSP) Reporting

Group health plans that are primary to Medicare must report coverage information to CMS so Medicare can coordinate benefits. Applies to employers with 20+ employees. Reporting entity is typically the GHP insurer or TPA (for self-insured).

What is Medicare Secondary Payer reporting?

When an employee (or spouse) is Medicare-eligible but still covered by your group plan, someone has to tell Medicare which coverage pays first. Section 111 reporting is how CMS finds out. The plan reports covered individuals quarterly so Medicare can coordinate benefits instead of paying claims it shouldn't.

Who reports, and what's your part?

The reporting entity is your carrier (fully insured) or your TPA (self-funded), not you. But they can only report what you give them. Your job is the inputs: accurate employee counts, timely enrollment data, and responses to their data requests for Medicare-eligible members.

Why your headcount matters

The 20-employee threshold decides whether your plan pays primary for working-aged Medicare-eligible employees. Cross it, or fall below it, and the coordination rules flip. If your headcount moved this year, tell your carrier or TPA. Wrong group size is the most common way employers poison this data without knowing it.

Related Reading

• COBRA for Spouses When an Employee Retires or Hits Medicare. It's Not as Simple as "36 Months."→