If you don’t enroll in Medicare Part B when you’re first eligible during what is known as your Initial Enrollment Period (IEP), you may face delays getting coverage as well as a late enrollment penalty. The only time you can safely defer enrollment past your IEP is if you or your legal spouse are working for what is considered a large employer and you have group health coverage through that same employer. In this case you have what’s called a Special Enrollment Period (SEP) to apply for Part B without penalty. (Note that the rules are different if you have ESRD).
Your SEP is 8 months from the end of your active employment or the end of the group coverage, whichever comes first. Note that retiree coverage and COBRA don’t count as active employer coverage and will not allow you a SEP. They are typically not considered primary coverage either and are secondary to Medicare whether or not you’ve actually enrolled in Medicare. That means that if you stop active employment and you’re eligible for Medicare but haven’t signed up, you will be without primary coverage even if you have a retiree plan or COBRA. These plans can recoup payments made in error.
Should you miss your IEP and not have a SEP then your only opportunity to enroll in Part B is during the General Enrollment Period (GEP). This is only during the first quarter of each year, Jan. 1 – March 31 and your coverage won’t start until July 1 of that year. Most people who enroll during the GEP will have a permanent late enrollment penalty added to their monthly Part B premium. The penalty is equal to 10% of the current year’s base Part B premium for each 12 month period that you were eligible for Medicare but not enrolled and did not have active employer group coverage.
It can be complicated so see HICAP Counseling for assistance.