Medicare and other insurance: who pays first?
Pick why you have Medicare and what other coverage you have. The checker applies the coordination of benefits rules in CMS's booklet How Medicare Works with Other Insurance: for example, at 65 or older, a current employer with 20 or more employees pays first and Medicare second.
Yours, your spouse's or a family member's employer. In a multi-employer plan, use the largest employer in the group.
Pays first
Your group health plan
- Pays second
- Medicare
At 65 or older with coverage from current work, an employer with 20 or more employees (or in a multi-employer group where one has 20 or more) pays first.
The rules behind the answer
| Situation | Pays first | Pays second |
|---|---|---|
| 65+, plan from current work, employer with 20+ employees | Group plan | Medicare |
| 65+, plan from current work, fewer than 20 employees | Medicare | Group plan |
| Under 65 with a disability, current employer with 100+ employees | Group plan | Medicare |
| Under 65 with a disability, fewer than 100 employees | Medicare | Group plan |
| Retiree plan (age or disability) | Medicare | Retiree plan |
| COBRA (age or disability) | Medicare | COBRA |
| ESRD, group, retiree or COBRA, first 30 months | That plan | Medicare |
| TRICARE, not on active duty | Medicare | TRICARE |
| TRICARE, on active duty | TRICARE | Medicare |
| Medicaid | Medicare | Medicaid |
Before you change anything
- If you have employer or union coverage and add a Medicare drug plan, CMS warns you may lose that coverage, including health coverage for your spouse or dependents, and may not get it back. Call the benefits administrator first.
- If your drug coverage is creditable, you can wait to join a Medicare drug plan without a penalty, as long as you do not go 63 days or more without creditable coverage.
- Medicare does not know about your other coverage on its own. Tell every doctor and pharmacy about all the coverage you have.
- Under 65, Social Security or Railroad Retirement disability benefits lead to Medicare after 24 months, with no wait for ALS. Until then, your group plan is your only payer.
- Accident, liability, no-fault and workers' compensation insurance pay first for care related to that claim.
The checker covers the common cases; CMS says its booklet does not cover every situation. For a definite answer, call the Benefits Coordination & Recovery Center at 1-855-798-2627 (TTY 1-855-797-2627). For the whole picture, read Medicare enrollment periods explained.
Check our work
Every figure on this page was read from these official documents. Follow the links and compare.
- How Medicare Works with Other Insurance (CMS Product No. 02179, February 2026)Centers for Medicare & Medicaid Services. Read on November 13, 2026.
- Who pays first?Centers for Medicare & Medicaid Services. Read on November 13, 2026.