How does my other insurance work with Medicare?


When you have other insurance (like employer group health coverage), there are rules that decide whether Medicare or your other insurance pays first.

If you have retiree insurance (insurance from your or your spouse’s former employment)… Medicare pays first.

If you’re 65 or older, have group health plan coverage based on your or your spouse’s current employment, and the employer has 20 or more employees…Your group health plan pays first.

If you’re 65 or older, have group health plan coverage based on your or your spouse’s current employment, and the employer has less than 20 employees…Medicare pays first.

If you’re under 65 and disabled, have group health plan coverage based on your or a family member’s current employment, and the employer has 100 or more employees…Your group health plan pays first.

If you’re under 65 and disabled, have group health plan coverage based on your or a family member’s current employment, and the employer has less than 100 employees…Medicare pays first.

If you have Medicare because of End‑Stage Renal Disease (ESRD)…Your group health plan will pay first for the first 30 months after you become eligible to enroll in Medicare. Medicare will pay first after this 30‑month period.

Note: In some cases, your employer may join with other employers or unions to form a multiple-employer plan. If this happens, the size of the largest employer/union determines whether Medicare pays first or second.

Here are some important facts to remember:
The insurance that pays first (primary payer) pays up to the limits of its coverage.
The insurance that pays second (secondary payer) only pays if there are costs the primary insurer didn’t cover.
The secondary payer (which may be Medicare) may not pay all of the uncovered costs.
If your employer insurance is the secondary payer, you may need to enroll in Part B before your insurance will pay.
Medicare may pay second if you’re in an accident or have a workers’ compensation case in which other insurance covers your injury or you’re suing another individual or entity for medical expenses. In these situations, you or your lawyer should tell Medicare as soon as possible.

These types of insurance usually pay first:
No-fault insurance (including automobile insurance)
Liability insurance (including automobile and self-insurance)
Black lung benefits
Workers’ compensation
Note: Medicare may pay conditionally if the no-fault, liability, or workers’ compensation insurance hasn’t settled on the claim.

Medicaid and TRICARE never pay first for services that are covered by Medicare. They only pay after Medicare, employer group health plans, and/or Medicare Supplement Insurance have paid.
For more information, visit Medicare.gov/publications to view the booklet “Medicare and Other Health Benefits: Your Guide to Who Pays First.” You can also call 1-800-MEDICARE (1‑800‑633‑4227) to find out
if a copy can be mailed to you. TTY users should call 1‑877‑486‑2048.

If you have other insurance, be sure to tell your health care provider, hospital, and pharmacy. If you have questions about who pays first, or you need to update your other insurance information, call Medicare’s Coordination of Benefits Contractor at 1‑800‑999‑1118. TTY users should call 1‑800‑318‑8782. You can also contact your employer or union benefits administrator. You may need to give your Medicare number to your other insurers so your bills are paid correctly and on time.