Should I enroll in Medicare Part A even if I don't retire?

A lot of people work past the age of 65, and some of them -- like you -- have health insurance coverage through their employer. It sounds like you will also continue to have health insurance coverage for yourself and your wife after you retire. The question of when to enroll in Medicare, and which parts of Medicare to enroll in, depends in part on whether you actually retire.

First, let's consider Medicare Part A. There's no reason for you to delay enrolling in Part A because coverage is free for anyone who has enough of a work record to claim Social Security retirement benefits (whether or not you actually claim them at age 65).

Medicare Part B is a different matter. If you continue to work and are covered by an employer-sponsored health insurance plans, there are several reasons why you might not want to sign up immediately for Medicare Part B. The first is that, as you've indicated, your wife can receive coverage through your work insurance. (She will be able to receive Medicare Part A coverage, based on your work record, and Medicare Part B coverage, as soon as she turns 65.) Another reason is that as long as you have your employer-sponsored insurance from your current work, that will be your primary coverage -- will pay your medical bills first -- with Medicare Part B kicking in only to help pay the parts your insurance doesn't pay. Since there is a monthly premium -- for most people, $96.40 a month in 2010 -- to pay for Medicare Part B, this may not be something you want to spend if Part B would only give you minor, secondary coverage. Finally, there is no penalty to you for delaying your enrollment in Medicare Part B after age 65, as long as you are still working and covered by an employer-sponsored health plan based on that current work.

The picture changes, though, if you retire. If you have health insurance as a retiree through your former employer, that insurance coverage may require you to sign up for Medicare Part B. That's because if you do sign up, Medicare Part B would become your primary health insurer -- paying the largest share of the bills -- while your retiree health insurance would be the secondary payer. Some retiree health plans therefore require you to enroll in Medicare Part B so that they are off the hook for the majority of your medical expenses. So, make sure to check with your benefits office at work to find out whether you would be required to sign up for Medicare Part B in order to keep your retiree health insurance.

There's another reason to enroll in Medicare Part B once you retire, which is that if you don't, you'll become subject to a penalty if and when you ever do sign up for Medicare Part B. Once you no longer have health insurance based on current employment, your Medicare Part B monthly premium will be 10 percent higher for every year you are not enrolled in Medicare Part B, if and when you ever do sign up for Part B (even if you still have retiree health insurance).