Aetna lifted its 4-star Medicare plans from 21% to 87% of members in one year
After a star-ratings collapse put $800M–$1B of insurance operating income at risk, Aetna rebuilt service and adherence: 87% of members now in 4+ star plans.
What was changed
For the 2023 plan year, Aetna's Medicare Advantage star ratings took a massive hit: just 21% of its members were in plans rated four stars or more. The largest factor was a one-star decrease on its National PPO Plan, which holds more than half of its MA membership — a drop CVS said would likely reduce 2024 operating income for the insurance business by between $800 million and $1 billion. CEO Karen Lynch had told the J.P. Morgan Healthcare Conference the company intended to rebound by 2025; analyst Lisa Gill noted few investors in the room believed it.
A year later at JPM24, the rebound had already landed: 87% of Aetna's MA members were in plans with at least four stars, making the insurer one of the stronger performers in the 2024 ratings. Lynch attributed it to cross-company work — fixing patient experience survey performance with 'every touchpoint within the company' pushing member service, taking a closer look at medication adherence and care management programs, and turning that into HEDIS measure gains. Her framing: 'we really built sustainable processes to make sure that we can continue to have that performance on an ongoing basis.'
The membership picture reversed too. Alongside the ratings decline a year earlier, Aetna had faced disappointing MA growth; for 2024 it expected to add 800,000 MA members, about a third in dual-eligible plans, with CVS's SEC filing describing open enrollment beyond expectations, significant retention, and 'a higher than historical proportion' of new sign-ups peeling off competitors.
Why it worked
The shortfall had a named cause: one star off the National PPO plan that holds over half of Aetna's MA membership.
The fix targeted the actual scored inputs: patient experience surveys, medication adherence and HEDIS care measures.
Lynch framed it as execution and process-building, so the performance would continue beyond one rating cycle.
The reversal carried into growth: 800,000 expected new MA members, with sign-ups switching from competitors.
What can be applied
Service metrics are money in Medicare: a one-star slide on one plan put nine figures of bonus revenue at risk, and the fix was unglamorous — surveys, adherence, care management, process.
Aftermath
CMS's methodology changes for the 2024 ratings left some payers out in the cold — Elevance Health filed a lawsuit in late December challenging the updates. Aetna's comeback arrived a year ahead of Lynch's promised 2025 rebound, with Q4 and full-year earnings due February 7.