Which individual enrolled based on a fixed enrollment period?

The choice indicating that Ben enrolled during the MA Open Enrollment Period is correct because it specifically refers to a defined time frame during which beneficiaries can enroll in or change their Medicare Advantage (MA) plans. The MA Open Enrollment Period typically occurs annually and is a designated period when eligible individuals can make changes to their MA coverage without any restrictions.

This timeframe is crucial because it ensures that individuals have the opportunity to make informed decisions regarding their healthcare plans at least once a year, aligning with Medicare policies meant to encourage optimal patient choice and coverage suitability. This form of enrollment stands out as it is based on an established schedule, contrasting with other choices that may not clearly indicate adherence to specific enrollment rules or periods.

The other options lack a direct reference to a fixed enrollment period: Mr. Ford's enrollment in an MA-only plan does not specify when he enrolled, Mrs. Johnson's completion of her enrollment does not indicate a particular enrollment period, and Mr. Anderson filling out a form in October does not provide clarity on whether this was within a recognized enrollment timeframe for Medicare. Thus, Ben's enrollment during the MA Open Enrollment Period is the only option explicitly grounded in a defined schedule.