2027 Medicare Part D Base Premium: What the New CMS Numbers Mean

On July 28, 2026, the Centers for Medicare & Medicaid Services released technical Medicare Part D bid information for 2027. CMS set the 2027 national base beneficiary premium at $41.33 and the national average monthly bid amount at $296.05.

These numbers help CMS and plan sponsors calculate parts of the Part D program. They are not a list of the premiums beneficiaries will pay. CMS says finalized 2027 Medicare Advantage and Part D offerings, final average premiums, and other key plan information are expected in mid-to-late September.

CMS describes the national base beneficiary premium as a starting point used to calculate a plan-specific basic Part D premium. A statutory formula uses plan bids and estimated reinsurance costs to produce the national base amount. The Inflation Reduction Act limits its annual increase to no more than 6% from 2024 through 2029.

Your actual 2027 premium could be lower or higher than $41.33. It will depend on the specific standalone Part D plan or Medicare Advantage plan with drug coverage available in your area, as well as plan design and any applicable adjustments. Do not treat the national base amount as a quote.

The national average monthly bid amount, often shortened to NAMBA, is an enrollment-weighted average of applicable plan bids for the basic Part D benefit. CMS uses it to calculate the government subsidy paid toward plan coverage.

Because it is a technical program calculation, the $296.05 figure should not be added to the $41.33 base amount or interpreted as the premium a person will owe. A beneficiary should use the plan-specific premium and cost information released for the plans actually offered in their ZIP code or county.

CMS also announced that the voluntary Part D Premium Stabilization Demonstration for standalone prescription drug plans will end after 2026. The demonstration began in 2025 to address premium volatility and variation after changes to the Part D benefit.

CMS says its 2027 bid analysis indicates that plan sponsors now have enough experience with the redesigned benefit to support their bid assumptions. The end of the demonstration does not reveal what any one plan will charge in 2027. Beneficiaries should wait for finalized local plan information before drawing conclusions about their own premium.

A low monthly premium does not necessarily mean the lowest total annual cost. Your medications, formulary placement, deductible, copays or coinsurance, pharmacy network, prior authorization, quantity limits, and other plan rules can matter as much as the premium.

When 2027 plans become available, enter your current prescriptions and preferred pharmacies in Medicare Plan Compare. Review the plan’s formulary and official documents, and ask the plan to confirm important coverage details. Drug lists and costs can change from year to year.

Medicare.gov explains that a Part D late-enrollment penalty is generally calculated using 1% of the national base beneficiary premium for each full uncovered month a person was eligible for Part D but did not have Part D or other creditable prescription drug coverage. The result is rounded and added to the monthly plan premium.

The national base amount can change each year, so a penalty can also change. Penalty rules depend on individual enrollment and coverage history, and people who get Extra Help do not pay a Part D late-enrollment penalty. Keep creditable-coverage notices and confirm your situation with Medicare or your plan.

For now, keep using your current 2026 plan and coverage information. Make a current medication list with exact drug names, dosages, quantities, and preferred pharmacies. Watch for your plan’s Annual Notice of Change, which explains changes taking effect the next year.

Medicare Open Enrollment runs from October 15 through December 7 for coverage beginning January 1. Once 2027 plan information is available, compare your current plan with other local choices even if you are satisfied today. You do not need to change plans simply because CMS released a new national base premium.

Ask: What is the plan-specific monthly premium? Are all my prescriptions on the formulary? What tiers and cost-sharing apply? Is my preferred pharmacy in network and preferred? Does the plan require prior authorization, step therapy, or quantity limits? What is the deductible?

If drug coverage comes through Medicare Advantage, also compare medical premiums, provider networks, copays, prior authorization, supplemental benefits, and the medical maximum out-of-pocket limit. A Part D premium headline does not identify one plan as best for everyone.

CMS: “Medicare Part D 2027 National Average Monthly Bid Amount Information,” released July 28, 2026. Medicare.gov: “How much does Medicare drug coverage cost?”, “Joining a plan,” and “Choose how you get drug coverage.” These official sources explain the preliminary 2027 figures, the difference between national calculations and plan premiums, Part D penalty basics, enrollment timing, and the main ways beneficiaries receive drug coverage.