Do I have to be retired to enroll in Medicare at age 65?
If you plan to continue working and your employer offers health benefits, you may wish to continue coverage through your employer and delay Medicare Part B coverage. However, you do need to check with your employer plan to determine whether Part B is required for full coverage. Examples of when Part B is required is when the employer group size is small enough that Medicare is primary coverage, or if you are in an unmarried domestic partner relationship (same or opposite sex).
If you choose to delay Part B coverage because you are enrolling in qualified employer sponsored health coverage, you will be eligible for a special enrollment period when your employer coverage ends. Enrolling timely in Part B allows you to avoid penalties that would otherwise apply.
If you enroll in your employer's HSA qualified plan, you need to be aware that you will need to disenroll in Part A as well as Part B coverage.
You may choose to enroll in Medicare coverage and continue to work. Typical considerations are the financial costs of the employer premium versus the Medicare premiums, and the employer benefit plan versus the Medicare benefit plan differences.