Your Medicare Plan's 2027 Changes Are Already Locked In. The Letter Arriving This Month Shows What Changed - If You Read It.

Medicare plans are required by federal law to mail every enrollee an Annual Notice of Change before October 15. The document contains the finalized 2027 premium, the updated formulary listing which drugs are covered and at what cost tier, and any changes to the provider network. Most people do not read it. The Annual Enrollment Period opens October 15 - and everything in that letter is already final.

What the Notice Actually Contains

The Annual Notice of Change is not marketing. It is a disclosure of confirmed changes that take effect January 1, 2027. If your plan raised its deductible, removed a medication from the formulary, changed the cost-sharing tier on a drug you take, or narrowed its network of covered specialists, that information is in the letter.

CMS requires plans to send these notices no later than September 30. They typically begin arriving in late August. The 2027 plan terms - including premium amounts, out-of-pocket maximums, and formulary changes - were finalized months ago.

The Change Most People Miss

Formulary changes are the most consequential and the least reviewed. A drug that was on Tier 2 (preferred generic) in 2026 may have moved to Tier 4 (non-preferred brand) in 2027, doubling or tripling your monthly copay. Plans are not required to notify you specifically about individual drug tier changes - only to send the ANOC document that contains them.

After 2.6 million seniors were pushed off Medicare Advantage plans in 2026 due to insurer exits, the 2027 enrollment period carries more consequence than usual.

What to Do Before October 15

When the Annual Notice of Change arrives, match your current medications against the 2027 formulary. If a drug has moved to a higher tier or been removed entirely, that is a qualifying reason to switch plans during AEP. Medicare.gov’s Plan Finder will update with full 2027 plan details starting October 1 - two weeks before enrollment opens. The free SHIP counseling line (1-800-633-4227) provides one-on-one help comparing plans at no cost.

References: 25 Health Systems Have Dropped Medicare Advantage in 2026: Here’s What Enrollees Should Do Now | 2026 Medicare Parts A & B Premiums and Deductibles