New Federal Guidance Says Some 2027 Medicare Advantage Plans May Stop Accepting New Members During Open Enrollment

On August 25, 2026, CMS released updated Medicare Advantage and Part D enrollment and disenrollment guidance for the 2027 plan year. A notable clarification addresses enrollment capacity limits. A Medicare Advantage plan that set a cap during the annual bid process may stop accepting new enrollees once it reaches that ceiling, even though the Annual Enrollment Period runs through December 7. CMS stated that plans that did not establish a capacity limit through the bid process cannot impose one later without specific CMS approval. Valid enrollment requests must be processed in the order received until any approved limit is reached. There is no public-facing indicator showing how close a plan is to its cap. A plan can appear fully available one day and closed to new applications the next, with no required advance warning to consumers or agents. The guidance also updates the definition of a lawfully present individual, revises default enrollment notices, clarifies loss-of-D-SNP-status notices, and updates information plans must provide about Medigap guaranteed-issue rights. All enrollment requests with a January 1, 2027 effective date, including those submitted during the fall 2026 Annual Enrollment Period, must be processed under the revised rules.