Approximately 2.4 million people enrolled in a Medicare Advantage plan from February 2020 to February 2021, bringing the total MA population to 26.3 million medical lives. That’s a 9.9% year-over-year increase, according to AIS Health’s analysis of data from the 2021 Medicare Annual Election Period (AEP). While the AEP was strong overall, the top 10 MA insurers continue to dominate the market, with 62.7% of all new enrollees selecting a plan from UnitedHealthcare, Humana Inc. or CVS Health Corp.’s Aetna. Meanwhile, Centene Corp.’s completed acquisition of WellCare Health Plans, Inc. allowed it to jump from No. 10 to No. 6, more than doubling its 2020 headcount. See a complete breakdown of the top 10 payers’ results below. No state saw any MA losses from 2020 to 2021, with 10 seeing increases of more than 20%, including several states with historically low penetration rates, such as Delaware, Maryland and Vermont (see map below).