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Coordination Of Benefits Basics

Primary and secondary payers

Understand payment order to make sure you aren’t left without primary insurance coverage.

Last Updated: March 23, 2025

When you have Medicare Medicare is the federal government health insurance program that provides health care coverage if you are 65 or older, are under 65 and receive Social Security Disability Insurance (SSDI) for 24 months, begin receiving SSDI due to ALS/Lou Gehrig’s Disease, or have End-Stage Renal Disease (ESRD) no matter your age. You can receive health coverage directly through the federal government (see Original Medicare) or through a private company (see Medicare Advantage).  and another type of insurance, Medicare will either pay primary or secondary for your medical costs.

  • Primary insurance pays first for your medical bills.
  • Secondary insurance pays after your primary insurance.
    • Usually, secondary insurance pays some or all of the costs left after the primary insurer has paid (e.g., deductibles, copayments, coinsurances). For example, if Original Medicare Original Medicare, also known as Traditional Medicare, is the fee-for-service health insurance program offered through the federal government, which pays providers directly for the services you receive. Almost all doctors and hospitals in the U.S. accept Original Medicare. is your primary insurance, your secondary insurance may pay for some or all of the 20% coinsurance The coinsurance is the portion of the cost of care you are required to pay after your health insurance pays. Usually, it is a percentage of the approved amount or negotiated amount. In Original Medicare, the coinsurance is usually 20% of Medicare’s assignment. for Part B-covered services. You may find secondary insurance useful in lowering your health costs depending on how much coverage your primary insurer offers and its costs.
    • If your primary insurance denies coverage, secondary insurance may or may not pay some part of the cost, depending on the insurance.
    • If you do not have primary insurance, your secondary insurance may make little or no payment for your health care costs.

If you are considering delaying Part B enrollment because you have insurance, make sure to ask your benefits manager or human resources department how your insurance works with Medicare. In cases where Medicare is primary to your current insurance, you should enroll in Part B to avoid incurring high costs for your care. This is because when Medicare is primary to your other insurance, your other insurance may not pay for costs until Medicare pays—so you would be responsible for paying these costs out of pocket. When Medicare is secondary, your current insurance will pay the majority of the cost for covered services.

You can also confirm how Medicare works with your current insurance by contacting the Social Security Administration (SSA) The Social Security Administration is the United States government agency responsible for managing various programs, including Medicare, Social Security Disability Insurance (SSDI), Supplemental Security Income (SSI), and Extra Help.  or Medicare.

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