If you aren't careful about the timing of your Medicare enrollment, you could make a very costly mistake -- one that will cost you for the rest of your life.
Here's a key fact to keep in mind. The "full retirement age" for Social Security is now well past age 66, but the first decision date for Medicare is at age 65 -- even if you are still working and covered by your employer.
Those who are already receiving Social Security at age 65 will be enrolled in Medicare automatically. Everyone else needs to determine what to do.
Diane Omdahl of 65incorporated.com, a Medicare benefits expert who advises corporate HR departments...