On July 29, 2026, CMS announced that the Part D Premium Stabilization Demonstration will not continue into 2027. The agency said plan sponsors now have enough experience under the redesigned drug benefit to return the program to "traditional market conditions."
For retirees, that sentence has a dollar figure attached to it.
What the Demonstration Was Doing
The demonstration was a temporary federal subsidy that held down standalone prescription drug plan premiums while insurers absorbed the benefit redesign. It worked in two ways: a flat reduction to the base premium, and a ceiling on how much any single plan could raise its premium year over year.
In 2025, that meant a $15 base reduction and a $35/month cap on increases. For 2026, it scaled back to a $10 reduction and a $50 cap. The Medicare Payment Advisory Commission estimated the subsidies cut average premiums by $26 in 2025 and $16 in 2026 — bringing the average standalone plan premium to roughly $36 a month this year. The Government Accountability Office put the two-year cost at $9.8 billion.
Starting January 2027, none of that support is in place. CMS set the 2027 national average monthly bid amount at $296.05 and expects most beneficiaries to see an increase of $10 or less per month, though it acknowledges some plans could rise more.
The 6% Cap Is Narrower Than It Sounds
The 2027 base beneficiary premium is $41.33, up from $38.99 — a 6% increase, which is the maximum allowed under the Inflation Reduction Act's growth cap through 2029.
Here is the part that trips people up. That cap applies to the base beneficiary premium, a national benchmark figure. It does not cap what your specific plan charges you. Individual plan premiums are set by insurers and can move well beyond 6% in either direction. Retirees who read "capped at 6%" and skip open enrollment are protecting a number that is not on their bill.
What Is Not Changing
The premium change does not touch the benefit itself. For 2027, CMS finalized a $2,400 out-of-pocket cap (up from $2,100 in 2026) and a $700 deductible in its April 6, 2026 Rate Announcement. The $35 monthly insulin cap remains. The catastrophic protection that made 2025 a structural improvement for high-drug-cost retirees is intact.
Practical Takeaways
- Do not act yet — but calendar it. CMS publishes the 2027 plan landscape in mid-to-late September. Plan-specific premiums are unknown until then.
- Read the Annual Notice of Change. Your plan must mail it before open enrollment. It shows your 2027 premium, deductible, and formulary changes side by side with 2026.
- Re-shop during open enrollment: October 15 – December 7, 2026. Use the Medicare Plan Finder and enter your actual medications. The lowest-premium plan is frequently not the lowest total-cost plan once the formulary and tier placement are applied.
- Budget a modest increase now. Adding $10–$25 a month per person to your 2027 healthcare line is a reasonable placeholder until September.
- If costs cluster early in the year, the Medicare Prescription Payment Plan lets you spread out-of-pocket drug costs across the calendar year instead of absorbing them in January.
- Watch the interaction with IRMAA. Higher-income retirees pay a Part D surcharge on top of the plan premium, based on income from two years prior. Both move independently.
The demonstration was always temporary. The planning error would be treating this year's premium as next year's baseline.
Sources: CMS – Medicare Part D 2027 National Average Monthly Bid Amount Information (July 29, 2026); Forbes – A Medicare Drug Subsidy Is Ending: Here's What Patients Should Know (July 31, 2026); Kiplinger – Medicare 2027: How Much Premiums Are Set to Rise; Managed Healthcare Executive – CMS Sets the 2027 Part D Bid Amount at $296.05, Will End Premium Subsidy Program; CMS – Contract Year 2027 Rate Announcement (April 6, 2026)
This article is for educational purposes only and is not tax, investment, or medical insurance advice. Consult a qualified professional about your specific situation.