You are not required to take Part B during your Initial Enrollment Period (IEP)  if you are still working or your spouse is still working and one of you has coverage as a result of that current work. (Discussions about your spouse’s insurance are relevant if you receive your health insurance coverage through them.)  You should only delay Part B if this current employer insurance (also called group insurance) is the primary payer on your health care expenses (meaning Medicare would pay after the employer insurance pays on a claim). You should talk to your employer (or your spouse’s employer) when you become eligible for Medicare to see how employer insurance will work with Medicare. Generally, if you are eligible for Medicare because you are over 65, the employer must have more than 20 employees to be the primary payer. If you are eligible for Medicare because you get SSDI, the employer must have more than 100 employees to be the primary payer.

If there are fewer than 20 employees at the company where you currently work or your spouse currently works, Medicare is your primary coverage. In this case, you should not delay enrollment into Part B. If you decline Part B, you will have no primary insurance, which is usually like having no insurance at all.

In either case, if you have insurance from a current employer, you qualify for a Special Enrollment Period (SEP). During this period, you can enroll in Part B without penalty at any time while you or your spouse is still working and for up to eight months after you lose employer coverage, switch to retiree coverage, or stop working.

It is important to remember that COBRA and retiree insurance are not considered current employer insurance, and you will not have a Special Enrollment Period to enroll in Medicare beyond the eight months you are given after you stopped working. If you have COBRA or retiree insurance and delay enrollment in Part B, you may have to pay a penalty when go to sign up.

If your work status changes, Medicare may change how it works with your employer insurance. An example of changes in work status includes retiring and taking COBRA. You should always call Social Security when your work status changes to ensure you are aware of any changes in your health care coverage and needed next steps.

If you were already collecting Social Security before you turned 65, or if you are eligible for Medicare due to disability, you will be automatically enrolled in both Medicare Part A and Part B. You can turn down Part B, but you will need to send back the Medicare card you received in the mail with the form you received stating that you do not want Part B. You will receive a new Medicare card in the mail that does not have Part B on it.

If you are thinking about turning down Part B—or enrolling in only Part A—you should call the Social Security Administration at 800-772-1213 and ask if you can defer enrollment without penalty.  Be sure to explain the type and source of your other insurance and other circumstances in as much detail as possible. When you call Social Security, make sure to write down whom you spoke to, when you spoke to them, and what they said.  As noted above, to avoid a penalty, you generally must be covered under employer health insurance that is available to you because of your or your spouse’s (or in more limited circumstances a family member’s) current work.  The rules for determining what counts as an employer health insurance plan and what counts as current work are specific, so be sure that your situation falls within the rules before you make a decision.