Medicare open enrollment ends December 7, 2026, and this year the deadline matters more than usual. About 1.2 million people on standalone Part D drug plans are in plans that end after December 31, 2026, according to a KFF analysis of CMS plan data published October 27, 2026. If you are one of them and you do nothing, your drug coverage stops on January 1.
The biggest group is SilverScript Choice, the CVS Health plan. Roughly 950,000 of the 1.2 million are in that plan, and it is leaving 13 of the 34 Part D regions for 2027. It stays in 22 states and Washington, D.C., so the same plan card can mean very different things depending on where you live. Aetna is also leaving the standalone Part D market in about half of states, according to an Oliver Wyman estimate reported in late October.
What changes in Part D for 2027
The Part D numbers for 2027 are final, and they are not gentle. The maximum deductible rises from $615 to $700, and the out-of-pocket cap rises from $2,100 to $2,400, per the CMS 2027 Rate Announcement. The national base beneficiary premium is $41.33 a month.
Choice is shrinking at the same time. There will be 316 standalone Part D plans from 15 companies in 2027, down from 360 plans from 17 companies in 2026, KFF found. The average person will have nine standalone plans to choose from, down from 11. And there will be no $0-premium standalone plan in 2027 for people who do not get Extra Help.
The cost of standing still is real. KFF’s October 30 analysis found that if standalone Part D enrollees stay in their current plans, the average premium would rise about 50 percent, from $34 to $51 a month. CMS projects the average premium at about $36 a month, but averages hide wide variation — some plans are rising far more than others. Part of the jump reflects the end of a temporary federal program that held premiums down in 2025 and 2026. CMS confirmed that demonstration ends after 2026.
The Part B number is still missing
One figure is still not official. The standard Part B premium for 2027 has not been announced by CMS as of today, November 9, 2026. The 2026 Medicare Trustees Report projects it at $209.50 a month, up $6.60 from $202.90, with the deductible projected at $292, up from $283. That is a projection, not a bill. CMS announced the 2026 figures on November 14, 2025, so a mid-November release is possible again — but it is a pattern, not a promise. The $6.60 increase, if it holds, would be the smallest since 2023, and it would take a small bite out of the 3.6 percent Social Security COLA that starts in January. See the January 2027 payment dates for when the first COLA checks arrive.
Medicare Advantage is shrinking too
The churn is not limited to drug plans. The CMS 2027 plan crosswalk dated October 1, 2026 lists 569 individual Medicare Advantage plans as terminated or non-renewed, covering about 2.15 million members — 9.9 percent of individual-plan members. KFF counted 193 counties with no Medicare Advantage prescription drug plan open to general enrollment for 2027, up from 123 a year earlier. If your plan is ending, your insurer had to send you a non-renewal letter by October 2, 2026. If you did not get one, your plan is continuing — but its premiums, drug list and pharmacy network may still have changed.
What happens if you miss December 7
Missing the deadline is not the end of the road, but the road gets narrower. If your plan is not renewing, you get a special enrollment period from December 8, 2026 through the last day of February 2027. A plan chosen by December 31 still starts January 1, so there is no gap. After that, a plan chosen later starts later, and the gap is real.
Medicare Advantage enrollees get a separate window, January 1 through March 31, 2027, to switch to another Advantage plan or back to Original Medicare. And people who qualify for Extra Help, Medicare’s low-income drug subsidy, are automatically enrolled in a new drug plan starting January 1 if they do not choose one by December 31.
Do not let the gap stretch. Going 63 days or more in a row without Part D or other creditable drug coverage can mean a late enrollment penalty, added to your premium for as long as you have drug coverage. The penalty is 1 percent of the national base beneficiary premium — $41.33 for 2027 — for each full month without coverage.
The practical move is simple: compare your 2027 options on Medicare.gov’s Plan Finder or by calling 1-800-MEDICARE (1-800-633-4227) before December 7. Check your drugs, your pharmacy and your premium — not just the plan name. A plan that keeps its name can still cost you far more next year.
Health insurance through the ACA has its own open enrollment deadline — December 15 for January 1 coverage.
FAQ: Medicare open enrollment ends December 7 2026
When does Medicare open enrollment end for 2027 coverage?
December 7, 2026. Changes made by then take effect January 1, 2027. The window opened October 15, 2026.
My Part D plan is ending. What happens if I do nothing?
Your drug coverage ends December 31, 2026. If your plan is not renewing, you get a special enrollment period through February 28, 2027, and a plan chosen by December 31 still starts January 1. After that, coverage starts later and you risk a gap.
Is SilverScript Choice ending everywhere?
No. It is leaving 13 of the 34 Part D regions for 2027, affecting about 950,000 members, but it stays in 22 states and Washington, D.C. Whether it continues for you depends on where you live.
What is the Part B premium for 2027?
Not officially announced yet. The Medicare Trustees project $209.50 a month, up from $202.90 in 2026, with the deductible projected at $292. CMS usually announces the final figures in mid-November.
What is the Part D late enrollment penalty?
If you go 63 days or more without Part D or other creditable drug coverage, you pay 1 percent of the national base beneficiary premium ($41.33 for 2027) for each full month without coverage, added to your premium for as long as you have drug coverage.
Sources
KFF, Medicare Part D enrollees in plans ending after 2026 analysis, Oct 27, 2026; KFF, Medicare open enrollment 2027 analysis, Oct 30, 2026; CMS, 2027 Part D fact sheet (Sep 28, 2026) and 2027 Rate Announcement (Apr 6, 2026); CMS, 2027 Part C and D Plan Crosswalk, Oct 1, 2026; CMS, 2026 Medicare Parts A and B Premiums and Deductibles fact sheet, Nov 14, 2025; 2026 Medicare Trustees Report (Part B premium projection $209.50); Medicare.gov, Special Enrollment Periods and Joining a plan; Oliver Wyman estimate via KEYT / Medical Daily, Oct 26, 2026.