Which insurance pays first

If the employer has more than 20 employees, the group health plan generally pays first.

If the group health plan didn't pay all of your bill, the doctor or health care provider should send the bill to Medicare for secondary payment. Medicare will look at what your group health plan paid, and pay any additional costs up to the Medicare-approved amount. You'll have to pay whatever costs Medicare or the group health plan doesn't cover.

Generally, employers with 20 or more employees must offer current employees 65 and older the same health benefits, under the same conditions, that they offer younger employees. If the employer offers coverage to spouses, they must offer the same coverage to spouses 65 and older that they offer to spouses under 65.

Generally, if your employer has less than 100 employees, Medicare pays first if you're under 65 or you have Medicare because of a disability.

Sometimes employers with fewer than 100 employees join with other employers to form a multi-employer plan. If at least one employer in the multi-employer plan has 100 employees or more, Medicare pays second.

If the employer has 100 employees or more, the health plan is called a large group health plan. If you're covered by a large group health plan because of your current employment or the current employment of a family member, Medicare pays second. 

If your employer has fewer than 20 employees, Medicare generally pays first.

But if your employer joins with other employers or employee organizations (like unions) to sponsor a group health plan (called a multi-employer plan), and any of the other employers have 20 or more employees, Medicare would generally pay second. Your plan might also ask for an exception, so even if your employer has fewer than 20 employees, you'll need to find out from your employer whether Medicare pays first or second.

Medicare pays first if a domestic partner is entitled to Medicare on the basis of age and has group health plan coverage based on the current employment status of his/her partner. 

Medicare generally pays second:

• When the domestic partner is entitled to Medicare on the basis of disability and is covered by a large group health plan on the basis of his/her own current employment status or the status of a family member (a domestic partner is considered a family member).
• For a 30-month coordination period when the domestic partner is eligible for Medicare on the basis of End-Stage Renal Disease (ESRD) and is covered by a group health plan on any basis.
• When the domestic partner is entitled to Medicare on the basis of age and has group health plan coverage on the basis of his/her own current employment status.

Medicare pays first for any Medicare-covered health care service you get if you don’t take group health plan coverage from your employer, unless you have coverage through an employed spouse, and your spouse’s employer has at least 20 employees.

Medicaid never pays first for services covered by Medicare. It only pays after Medicare, employer group health plans, and/or Medicare Supplement (Medigap) Insurance have paid.

In general, the rules that apply to group health plan coverage also apply to COBRA continuation coverage. For example, if you or your spouse are retired and have COBRA continuation coverage, Medicare pays first.

If you have Medicare based on End-Stage Renal Disease (ESRD), COBRA continuation coverage pays first. Medicare pays second to the extent COBRA coverage overlaps the first 30 months of Medicare eligibility or entitlement based on ESRD.

Find out more in 7 facts about COBRA. 

If you go outside your employer plan's network, you might not get any payment from the plan or Medicare. Call your employer plan before you go outside the network to find out if the service will be covered.

If you have Medicare and more than one other type of insurance, check your policy or coverage—it may include the rules about who pays first. You can also contact the Medicare Coordination of Benefits Contractor.

In general, Medicare pays first for Medicare-covered services. TRICARE will pay the Medicare deductible and coinsurance amounts and for any service not covered by Medicare that TRICARE covers. You pay the costs of services Medicare or TRICARE doesn't cover.

If you get services from a military hospital or any other federal health care provider, TRICARE will pay the bills. Medicare usually doesn't pay for services you get from a federal health care provider or other federal agency. Get more information on TRICARE.  

If you have or can get both Medicare and Veterans' benefits, you can get treatment under either program. When you get health care, you must choose which benefits to use each time you see a doctor or get health care. Medicare can't pay for the same service that was covered by Veterans' benefits, and your Veterans' benefits can't pay for the same service that was covered by Medicare.  

If the VA authorizes services in a non-VA hospital, but doesn't pay for all of the services you get during your hospital stay, then Medicare may pay for the Medicare-covered part of the services the VA doesn't pay for. Medicare may also be able to pay all or part of your copayment if you're billed for VA-authorized care by a doctor or hospital who isn't part of the VA.

If you have a fee-basis ID card, you may choose any doctor listed on your card to treat you. If the doctor accepts you as a patient and bills the Department of Veterans Affairs (VA) for services, the doctor must accept the VA's payment as payment in full. The doctor can't bill you or bill Medicare for these services.

If your doctor doesn’t accept the fee-basis ID card, you'll need to file a claim with the VA yourself. The VA will pay the approved amount either to you or to your doctor.

If you're eligible for Medicare because of ESRD, your group health plan will pay first on your hospital and medical bills for 30 months, whether or not you're enrolled in Medicare. During this time, Medicare pays second.

This period of time is called a 30-month coordination period and usually starts the fourth month of dialysis. However, if you take a course in self-dialysis training or get a kidney transplant during the 3-month waiting period, your 30-month coordination period will start the first month of dialysis or kidney transplant.

The group health plan pays first during this period no matter how many employees work for your employer, or whether you or a family member are currently employed. At the end of the 30 months, Medicare pays first. This rule applies to most people with ESRD, whether you have your own group health plan coverage, or you're covered as a family member.

For all health care not related to black lung disease, Medicare pays first, and you should send your bills directly to Medicare.

The Federal Black Lung Program pays first for any health care for black lung disease covered under that program. Medicare won't pay for doctor or hospital services covered under the Federal Black Lung Program.

Your doctor or other health care provider should send all bills for the diagnosis or treatment of black lung disease to:

If the Federal Black Lung Program won't pay your bill, ask your doctor or other health care provider to send Medicare the bill. Ask them to include a copy of the letter from the Federal Black Lung Program that says why it won’t pay your bill.

No-fault insurance or liability insurance pays first and Medicare pays second, if appropriate.

If the no-fault or liability insurance denies the medical bill or is found not liable for payment, Medicare pays the same as it would if it were the only payer. However, Medicare only pays for Medicare-covered services; you're responsible for your share of the bill—for example, coinsurance, a copayment or a deductible—and for services Medicare doesn't cover.

If doctors or other providers are told you have a no-fault or liability insurance claim, they must try to get payments from the insurance company before billing Medicare. However, this may take a long time. If the insurance company doesn't pay the claim promptly (usually within 120 days), your doctor or other provider may bill Medicare. Medicare may make a conditional payment to pay the bill, and then later recover any payments the primary payer should have made.

If Medicare makes a conditional payment, and you get a settlement from an insurance company later, the conditional payment from your settlement needs to go to Medicare. You're responsible for making sure Medicare gets repaid for the conditional payment .

If you have an insurance claim for your medical expenses, you or your attorney should notify Medicare as soon as possible. If you have questions about a no-fault or liability insurance claim, call the insurance company.

If you have Medicare and get injured on the job, workers' compensation pays first on health care items or services you got because of your work-related illness or injury.

Find out more about how settling your claim affects Medicare payments.