Up to 5 million Medicare Advantage enrollees face the loss of their current health plans in 2027, nearly doubling the 2.6 million beneficiaries affected by plan exits this year. The projected disruption stems from payment-policy changes the Centers for Medicare and Medicaid Services finalized for Contract Year 2027, which tighten risk-adjustment rules and restructure Part D economics in ways that squeeze the margins of smaller, regional insurers hardest. For seniors who built their care around a specific network of doctors, pharmacies, and supplemental benefits, the practical result is a forced return to plan shopping during open enrollment or an automatic reassignment to a plan they did not choose.
Why the 2027 payment rules threaten a wave of MA plan exits
CMS each year publishes plan crosswalk files that map which plans terminate, which reduce their service areas, and which crosswalk enrollees into a successor product. The 2026 crosswalk file documents the 2.6 million beneficiaries whose 2025 plans either ended or shrank their coverage footprint heading into 2026. That figure already marked a sharp increase over prior years. A near-doubling to 5 million in 2027 would represent the largest single-year disruption since Medicare Advantage enrollment began its rapid expansion.
The mechanism behind the expected acceleration is financial, not demographic. CMS has finalized payment policies for 2027 that recalibrate how insurers are reimbursed for sicker patients and shift cost-sharing structures in the Part D drug benefit. Plans that operated on thin margins in rural or mid-sized metro counties now face a tighter revenue ceiling at the same time their prescription-drug obligations grow. When the math stops working, insurers pull out of counties or terminate plans entirely, and enrollees land in the crosswalk file.
Larger national carriers such as UnitedHealthcare and Humana have historically absorbed displaced members when regional competitors exit. The 2027 rule changes could intensify that pattern. Bigger insurers can spread risk-adjustment losses across millions of members and dozens of states. A regional plan covering three or four counties has no such cushion. The result is a market that consolidates faster than the crosswalk data alone would predict, concentrating more seniors into fewer plan choices and amplifying the impact of any single carrier’s strategic retreat.
CMS crosswalk data and the Contract Year 2027 final rule
Two primary data sources anchor the 2027 outlook. The 2026 Part C and D crosswalk download provides the baseline: it records every plan termination and service-area reduction that moved 2.6 million beneficiaries between 2025 and 2026, including whether they were mapped to a new plan under the same contract or forced to select a different sponsor. Analysts use these records to estimate how many additional exits would be required to displace another 2 to 3 million people in a single year, given current enrollment patterns and county-level plan density.
The second source is the Contract Year 2027 Medicare Advantage and Part D final rule, detailed in a CMS fact sheet. That regulation layers operational and compliance changes on top of the payment policies, including tighter guardrails on marketing, prior authorization, and supplemental benefits. While framed as beneficiary protections, these requirements add administrative cost, particularly for smaller organizations that lack large compliance departments. Combined with the payment shifts, they raise the threshold enrollment needed for a plan to remain viable in lower-density markets.
Together, the crosswalk history and the 2027 rule text point toward a scenario in which more contracts either consolidate their offerings or abandon marginal counties. Plans that already trimmed benefits or narrowed networks in 2025 and 2026 have limited room left to adjust. For those sponsors, exiting a product line may be the only way to avoid operating at a loss once the new rules take effect.
What it means for beneficiaries and local markets
For individual enrollees, the most visible consequence is disruption rather than outright loss of coverage. When a plan exits, affected members receive notices outlining their options, and many are automatically mapped to a “similar” plan offered by the same company. But similarity on paper can mask meaningful changes in premiums, deductibles, drug formularies, and provider networks. A senior who picked a plan because it covered a specific cardiologist or diabetes medication may discover during the next plan year that those anchors no longer fit within the new benefit design.
In counties dominated by a single regional carrier today, the 2027 changes could also alter the competitive landscape. If that carrier withdraws, the remaining choices may be limited to a few national brands with standardized benefit packages. While those plans can be stable, they may not replicate the tailored extras-such as transportation, dental coverage, or local care-management programs-that differentiated community-based insurers. Over time, this shift could erode the diversity of plan designs that has been a hallmark of Medicare Advantage’s growth.
Policymakers will be watching the next two years of crosswalk data closely. If the 5 million displacement estimate proves accurate, pressure may build for CMS or Congress to revisit certain elements of the 2027 framework, especially in rural and underserved areas. For now, beneficiaries, advocates, and providers have a narrow window to prepare for a more volatile Medicare Advantage marketplace, where staying in the same plan from one year to the next can no longer be taken for granted.
