Even if you keep working after you turn 65, you should sign up for Medicare Part A. If you have health coverage through your employer or union, Part A may still help pay some of the costs not covered by your group health plan. Call the Social Security Administration at 1-800-772-1213 to sign up. However, you may want to wait to sign up for Medicare Part B if you or your spouse are working and have group health coverage through you or your spouse's employer or union. (See note below if you work for a small company.)
However, you can defer Medicare Part B. More information can be found here:
**All above answers are provided as general information only. No warranty is made regarding the fitness or accuracy of the information provided in this answer. You should seek advice from a licensed CPA, attorney or CERTIFIED FINANCIAL PLANNER™ as to your unique financial situation.