When you have Medicare 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 is your primary insurance, your secondary insurance may pay for some or all of the 20% coinsurance 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) or Medicare.