Enrollment in Medicare Advantage (MA) has steadily increased over the last two decades, and as of 2022, nearly half (45.7 percent) of all Medicare recipients were in an MA plan. This brief identifies patterns and trends in MA participation (penetration rates, number of plans, and enrollment), both within and across metropolitan and nonmetropolitan counties.

Key Findings:

• From 2017 through 2022, growth (measured as percent increase) in the number of MA plans and MA enrollment rates was higher in noncore and micropolitan counties than in metropolitan counties, but metropolitan enrollment rates remained higher than nonmetropolitan enrollment rates. The median number of MA plans in metropolitan counties is higher than that in micropolitan counties which is higher than the median number of plans in noncore counties.
• Within each rural-urban classification, percent growth in MA penetration rates, plans, and enrollment has been highest in counties with the lowest participation rates in 2017.
• Population size is closely tied to higher participation rates both within and across geographic classifications, with the important caveat that micropolitan and noncore counties with higher MA participation exceed rates that population only would suggest.