Medical Expense✓ Verified · outline & fact-checked · Sep 2026Difficulty 2/5
When a person becomes eligible for Medicare Part B at age 65, the Initial Enrollment Period (IEP) lasts:
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Answer & full 3-part explanation (select an option above, or peek)
Why A is correct
The Part B Initial Enrollment Period is a 7-month window: 3 months before the month the individual turns 65, the birthday month itself, and 3 months after. Enrolling during this window avoids the late-enrollment penalty. The exam also tests the 8-month Special Enrollment Period (SEP) for people who delayed Part B while covered by employer group coverage, and the annual General Enrollment Period (GEP) of January 1 through March 31.
Why the other options are wrong
- B) The IEP is 7 months, not 5; the 3-before/1/3-after structure is the statutory window.
- C) The IEP is not a full year; it is anchored to the birthday month with 3 months on each side.
- D) Three months is only the back half of the IEP; the window also includes the 3 months before the birthday month.
Memory hook
IEP = 3 + 1 + 3 = 7 months around your 65th birthday. Miss the window, meet the penalty.