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Deciding if and when to enroll in the various parts of Medicare, when you are first eligible, is an important choice. In this blog post, we will explain how to make informed Medicare enrollment decisions and avoid penalties or gaps in coverage.

First, let’s review how age and job-based health insurance affect Medicare enrollment.

You may be able to delay Medicare Part B enrollment if you have health insurance from your current employer or your spouse’s current employer. You have a Special Enrollment Period (SEP) to enroll in Part B up to eight months after either the coverage or the current work ends, whichever is first. This SEP lets you enroll in Medicare after your Initial Enrollment Period (IEP) without a late enrollment penalty and without having to wait for the General Enrollment Period (GEP). In most cases, though, you should only delay enrolling in Medicare if your job-based insurance would be the primary payer, meaning it would pay first for your medical bills and Medicare would pay second. This will depend on your age and the size of your employer. If you are 65 or older, your job-based insurance pays primary if the employer has 20 or more employees. If you are eligible for Medicare due to disability, your job-based insurance is primary if the employer has 100 or more employees. Even if employer coverage would be your primary insurance, you might consider enrolling in Medicare if you want a secondary insurance to help cover the cost of your care. Additionally, many who delay Part B decide to still enroll in Part A, because it is usually premium-free.

You can contact your human resources department to learn about how your job-based insurance would work with Medicare. We encourage you to call your local State Health Insurance Assistance Program (SHIP) to review the information you learned from your employer since SHIP counselors are trained and trusted to provide accurate and unbiased Medicare information. Use our online SHIP Locator or call 877-839-2675 (and say “Medicare” when prompted).

Next, we can learn how other types of health insurance affect Medicare enrollment. 

If you have another kind of health insurance when you become Medicare-eligible, it is important to know how it works with Medicare and when you should enroll in Medicare.

  • Retiree insurance almost always pays second to Medicare, meaning you need to enroll in Medicare when first eligible or when you retire so you are fully covered. One exception is Federal Employee Health Benefits (FEHB) retiree coverage. FEHB retiree plans continue paying primary for retirees who do not enroll in Part B. FEHB retiree plans only become secondary if you do enroll in Part B.

  • If you have a Qualified Health Plan from the Marketplace, you should almost always disenroll from it and enroll in Medicare when you become eligible.

  • If you have COBRA, it is very important to enroll in both Part A and Part B. Your COBRA continuation rights usually terminate if you have COBRA before Medicare, and if you have Medicare Part A before you elect COBRA, the continuation coverage is secondary to Medicare and may not pay at all for outpatient care if you do not enroll in Part B.   

  • If you have VA coverage and choose not to enroll in Medicare, you will not have health insurance for facilities outside the VA health system. You should sign up for Medicare when you become eligible if you want to get covered health care outside the VA system.

Note that having any of these types of insurance does not grant you a Special Enrollment Period (SEP) if you decide to delay Medicare enrollment. If you don’t enroll in Medicare when you are first eligible because you have one of these types of insurance, you will likely face lifetime premium penalties and a gap in coverage if you later enroll in Medicare.

If you want to learn more about how your insurance may coordinate with Medicare, contact your local SHIP. Use our online SHIP Locator or call 877-839-2675 (and say “Medicare” when prompted).

And finally, it is important to understand considerations around Part D enrollment. 

If you are considering delaying Part D enrollment because you already have prescription drug coverage, first contact your human resources department to find out if your coverage is considered creditable. Creditable drug coverage is as good as or better than the standard Medicare Part D drug benefit. If you have creditable drug coverage, you will not have a late enrollment penalty for delaying Part D enrollment, and you will have an SEP to enroll in a Part D plan. Make sure to keep a record of your credible drug coverage if you are delaying Part D enrollment, since you may need this documentation to sign up for Medicare later. If you have no drug coverage, or have drug coverage that is not creditable, you must enroll in Part D when you are initially eligible to avoid a late enrollment penalty or gaps in coverage.

Wondering how to enroll, once your decisions are made?

To enroll in Medicare Part A or Part B, contact the Social Security Administration by calling 1-800-772-1213, by visiting, or by requesting an appointment at a local office. You can enroll in a Part D plan by visiting, by calling 1-800-MEDICARE, or by calling the plan of your choice directly.

Still have questions?   

Your SHIP is here for you! You can contact your SHIP for questions about your Medicare costs and coverage and any Medicare problems that arise. SHIP counselors are government funded to provide trusted, unbiased Medicare counseling at no cost to you. (Depending on your state, your SHIP may go by another name.)   

Use our online SHIP Locator or call 877-839-2675 (and say “Medicare” when prompted).

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