Quick Answer: Medicare Part D is the prescription drug benefit available since 2006 to anyone enrolled in [Medicare](/medicare-eligibility). Plans are offered as standalone Prescription Drug Plans (PDPs) or bundled into Medicare Advantage. The Inflation Reduction Act capped 2026 out-of-pocket drug costs at $2,100 and set a $35/month limit on insulin. Low-income enrollees may qualify for Extra Help, a federal subsidy that reduces or eliminates premiums and cost-sharing.
Annual Medicare Part D Limits
Current annual limits| Feature | 2026 Amount | Notes |
|---|
| Out-of-pocket cap | $2,100 | After cap: $0 cost-sharing (catastrophic) |
| Insulin (any covered brand) | $35/month max | IRA cap, effective 2023 |
| Recommended vaccines | $0 | Shingles, flu, COVID-19, others |
| Avg monthly premium | ~$40-55/month | Varies by plan; higher earners pay IRMAA surcharge |
Source: CMS Medicare Part D 2026 parameters (cms.gov). IRMAA surcharges apply above $106,000 individual income.
Source: https://www.cms.gov/medicare/prescription-drug-coverage/prescriptiondrugcovgenin
Standalone PDP vs. Medicare Advantage Drug Coverage
Part D comes in two forms. A standalone Prescription Drug Plan (PDP) pairs with Original Medicare (Parts A and B). Medicare Advantage plans (Part C) typically bundle drug coverage, so you don't need a separate PDP. You cannot hold both at the same time. Each plan has its own formulary: a tiered list from generic (Tier 1) to specialty (Tier 5), with cost-sharing rising at higher tiers. Formularies change annually; review your plan's Annual Notice of Change each fall before the Medicare Annual Enrollment Period. If you are comparing plans, does Medicare cover prescription drugs explains what Part D actually covers and where gaps remain. Low-income enrollees may qualify for Extra Help, which can nearly eliminate Part D cost-sharing.
Frequently Asked Questions
What is the 2026 Medicare Part D out-of-pocket cap?
$2,100 in 2026. Once your total out-of-pocket drug spending hits that threshold, you enter catastrophic coverage and pay $0 for the rest of the plan year. This cap was created by the Inflation Reduction Act and 2026 threshold is $2,100, up from $2,000 in 2025. See the CMS 2026 parameters at [cms.gov](https://www.cms.gov/medicare/prescription-drug-coverage/prescriptiondrugcovgenin) for details. If a drug bill looks wrong, use the [medical bill analyzer](/medical-bill-analyzer) to check it.
What is the late enrollment penalty for Part D?
1% of the national base beneficiary premium for each full month you went without Part D or other creditable drug coverage after becoming eligible. The penalty is permanent. Creditable coverage from an employer or union plan avoids it entirely; keep the annual creditable coverage notice your plan sends each fall.
Who qualifies for Extra Help with Part D costs?
Extra Help (the Low Income Subsidy) is a federal program for Medicare enrollees with limited income and resources. In 2026, eligibility generally requires income at or below about 150% of the [federal poverty level](/federal-poverty-level). Extra Help reduces or eliminates Part D premiums, deductibles, and copays. Apply at ssa.gov.
