A person who misses the initial enrollment period and the special enrollment period for Medicare Part B may enroll during the general enrollment period, which runs:

Why A is correct

The Medicare Part B general enrollment period (GEP) runs from January 1 through March 31 each year. Enrollment during the GEP avoids having to wait an entire additional year, but it still triggers the late enrollment penalty because the person missed both the initial enrollment period and any applicable special enrollment period. The GEP is distinct from the Medicare Advantage and Part D annual election period, which runs from October 15 through December 7. January 1 through March 31 is therefore the correct window for the Part B general enrollment period.

Why the other options are wrong

• B) October 15 through December 7 is the annual election period for Medicare Advantage and Part D plan changes, not the Part B general enrollment period. The October-December window belongs to Medicare Advantage and Part D plan changes, not Part B.
• C) The GEP spans three months rather than a single April month; April is not a Medicare enrollment window. No Medicare enrollment window is limited to a single month in April.
• D) Year-round enrollment is not available for Part B; the GEP is limited to the January-through-March window, with late penalties applying. Part B enrollment is restricted to defined windows, so year-round sign-up is not available.

Memory hook

GEP = the January-March catch-up window. Miss it and you wait a year and pay a penalty.