Not everyone retires at age 65, of course. If you choose to continue working, you may wonder how that affects your Medicare benefits — especially if you are still covered under your employer’s health plan. Here’s what you should know:

You can delay Medicare Part B Coverage

When you sign up for Original Medicare, you will have the option of delaying Part B. If you choose to do this, you may be able to sign up for Part B during a special enrollment period — which lasts for eight months after your employment or the group health coverage ends, whichever happens first.

How Medicare will work with your employer coverage

When you have a health plan in addition to Original Medicare, there are rules to determine whether Original Medicare or your other insurance pays first. The insurance that pays first is called the "primary payer" and pays up to the limits of its coverage. The other insurance, called the "secondary payer," only pays if it covers any of the costs left uncovered by the primary plan.

If your other coverage is provided by an employer or union group, these rules apply:

• If you are retired, Original Medicare pays first.
• If your coverage is based on current employment, the "primary payer" depends on your age, the size of the employer and whether you have Original Medicare based on age, disability or End Stage Renal Disease (ESRD):
  • If you are under age 65 and disabled, your plan pays first if your employer has 100 or more employees.
  • If you are over age 65 and still working, your plan pays first if your employer has 20 or more employees.
• If you have Original Medicare because you have ESRD, your plan always pays first for the first 30 months you have Original Medicare.

To be safe

Ask your employer to walk you through all of your health insurance options as you transition to Original Medicare.

If you do have health insurance other than Original Medicare, be sure to tell your doctor, hospital and pharmacist, so that your bills are paid correctly.