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Medicare Part D 2026: Costs, IRMAA Surcharges, and How to Choose a Drug Plan

Medicare Part D covers prescription drugs — but the costs depend on your income, whether you enrolled on time, and which plan you choose. In 2026, the Inflation Reduction Act's $2,100 out-of-pocket cap is fully in effect, eliminating the notorious "donut hole." Here's how the benefit works, what you'll actually pay at different income levels, and how to avoid the mistakes that make Part D more expensive than it needs to be.

2026 Part D benefit structure

In 2026, Part D coverage flows through three phases:1

Phase What triggers it What you pay
Deductible phase First $615 of covered drug costs 100% (up to the plan's deductible — some plans have lower or $0 deductible)
Initial coverage phase After deductible, until your out-of-pocket spending reaches $2,100 25% of each drug's cost (your plan pays 75%)
Catastrophic phase After $2,100 out-of-pocket $0 — no copays, no coinsurance for the rest of the year
The donut hole is gone. Before 2025, there was a coverage gap between the initial coverage limit and catastrophic coverage where you paid up to 25% (generics) or more (brand-name) of drug costs. The Inflation Reduction Act eliminated this gap starting in 2025. In 2026, you pay 25% throughout the initial coverage phase — with no sudden spike in costs in the middle.

The $2,100 out-of-pocket cap means your maximum exposure for covered drugs in any calendar year is $2,100 — no matter what your drugs actually cost. This is a major improvement for people on expensive brand-name medications or specialty drugs. Note that what counts toward your $2,100 cap includes drug manufacturer discounts, not just cash you pay directly.

The standard 2026 deductible is $615. No Part D plan may have a deductible exceeding $615, though many plans (particularly those with higher premiums) offer a lower deductible or none at all. Medicare Advantage plans with built-in drug coverage (MA-PD plans) often have lower or zero deductibles.

Late enrollment penalty calculator

If you don't enroll in Part D when you're first eligible — and you don't have creditable prescription drug coverage elsewhere (from an employer or union plan) — you'll owe a permanent late enrollment penalty added to your monthly premium for as long as you have Part D coverage.2

The penalty: 1% of the national base beneficiary premium × number of full uncovered months. For 2026, the national base beneficiary premium is $38.99, so the penalty is approximately $0.39 per uncovered month, rounded to the nearest $0.10.

Count from the end of your initial enrollment period to when you actually enrolled. Employer/union coverage is creditable — verify in writing with your plan.

The penalty never disappears. A retiree who went 3 years (36 months) without Part D or creditable coverage would pay roughly $14/month extra for the rest of their life. Over 20 years of retirement that's more than $3,400 in cumulative penalties — on top of the premiums they'd pay anyway.

Part D IRMAA: income-related premium surcharges

Like Part B, Medicare Part D charges higher-income beneficiaries a surcharge — the Income-Related Monthly Adjustment Amount (IRMAA). The Part D IRMAA is added to your drug plan's regular premium and paid directly to Medicare, not to your plan.3

Medicare uses your 2024 federal tax return (MAGI) to determine your 2026 IRMAA. MAGI for IRMAA purposes includes Social Security benefits, traditional IRA/RMD withdrawals, Roth conversion amounts, capital gains, wages, and most other taxable income. Roth withdrawals do not count.

2026 Part D IRMAA surcharges by income tier

2024 MAGI — Single 2024 MAGI — Married filing jointly Monthly surcharge Annual extra cost
$109,000 or less$218,000 or less$0$0
$109,001 – $137,000$218,001 – $274,000$14.50$174
$137,001 – $171,000$274,001 – $342,000$37.50$450
$171,001 – $205,000$342,001 – $410,000$60.40$725
$205,001 – $500,000$410,001 – $750,000$83.70$1,004
Above $500,000Above $750,000$91.00$1,092

Source: CMS 2026 Medicare IRMAA tables. Tier 5 thresholds ($500K single / $750K MFJ) are frozen through 2027 by statute. Values verified against the CMS fact sheet, November 2025.

Part D IRMAA stacks on top of Part B IRMAA. If your income triggers IRMAA, you pay the surcharge on both Part B and Part D. A single retiree with $175,000 MAGI pays an extra $324.60/month in Part B surcharges and $60.40/month in Part D surcharges — $4,620/year combined. See the IRMAA calculator for your combined Part B + D cost.

Part D IRMAA lookup

Enter your estimated 2024 MAGI to see your 2026 Part D surcharge:

Include SS benefits, RMDs, Roth conversions, capital gains, wages — but not Roth distributions.

Extra Help: eliminating Part D costs for lower-income retirees

If you have limited income and resources, you may qualify for the Extra Help program (also called the Low Income Subsidy, or LIS). Extra Help can substantially reduce or eliminate your Part D premium, deductible, and copays.4

Extra Help tier What it covers
Full Extra Help (Level 1) No premium, no deductible, minimal copays ($1.10–$3.40 for generics, $3.40–$10.35 for brand-name in 2026). Automatic if you have full Medicaid, SSI, or a Medicare Savings Program.
Partial Extra Help (Level 2) Reduced premium and deductible, small copays. Income and asset limits apply — contact SSA or your State Health Insurance Assistance Program (SHIP) to check eligibility.

Extra Help eligibility is based on your current-year income and assets — not the two-year lookback that applies to IRMAA. Income limits change annually. Apply through the Social Security Administration at SSA.gov or by calling 1-800-772-1213. Applications are free and there's no deadline — you can apply at any time.

If you automatically qualify (Medicaid, SSI, Medicare Savings Program), you'll be enrolled automatically and assigned to a benchmark plan. You can always switch to a different qualifying plan during open enrollment.

How to choose a Part D plan

If you use Original Medicare plus a standalone Medigap plan, you need a separate Part D drug plan. Every October 15 – December 7 is the Annual Enrollment Period (AEP) — when you can switch plans for coverage starting January 1. Here's how to evaluate plans:

1. Check your specific drugs first

Each Part D plan has its own formulary — a list of covered drugs organized by tier (generic, preferred brand, non-preferred brand, specialty). A drug that's Tier 2 on one plan might be Tier 4 on another, at dramatically different cost to you. Use Medicare.gov's Plan Finder tool and enter your actual drugs to compare total annual costs across plans.

2. Look at total annual cost, not just the premium

A $0-premium plan can cost more than a $35/month plan if it puts your drugs on higher tiers or has a full $615 deductible. The Plan Finder tool calculates estimated annual drug cost (premium + deductible + copays) based on your drug list. Sort by total annual cost, not premium.

3. Verify your pharmacy is in-network

Part D plans have pharmacy networks. Using a preferred network pharmacy often reduces your copays substantially. Check that your pharmacy (or a preferred pharmacy near you) is in-network before enrolling. Mail-order pharmacies typically offer the lowest costs for maintenance medications.

4. Check the plan's star rating

Medicare rates Part D plans 1–5 stars on quality and member experience. Five-star plans have a special enrollment period that lets you switch at any time during the year — not just during AEP. All else equal, prefer 4- or 5-star plans.

5. Check for Extra Coverage in the Catastrophic Phase

All Part D plans now cap your OOP at $2,100. Beyond that, you pay nothing. Some plans — particularly those through Medicare Advantage — offer additional dental, vision, or hearing benefits that standalone Part D plans don't include.

Medicare Advantage with drug coverage (MA-PD)

Medicare Advantage plans (Part C) almost always include prescription drug coverage — these are called MA-PD plans. If you choose Medicare Advantage instead of Original Medicare + Medigap, your drug coverage is bundled with your medical coverage in one plan.

Key differences from standalone Part D:

For more on the Original Medicare vs. Medicare Advantage choice, see our Medicare enrollment guide.

Planning your income to manage Part D IRMAA

Because Medicare uses your income from two years ago, a large Roth conversion, required minimum distribution, or capital gain in 2024 affects your 2026 Part D premium. Several strategies can reduce or eliminate your IRMAA surcharge:

For a full picture of how all retirement income sources interact with IRMAA, see the Retirement Income Tax Calculator or 7 strategies to minimize taxes in retirement.

Get matched with a fee-only retirement advisor

Coordinating Part D with your Roth conversions, RMDs, QCDs, and IRMAA cliff requires modeling your full retirement income picture. A fee-only advisor who specializes in retirement planning can find the strategies that save you money across healthcare and taxes — without a financial incentive to sell you anything.

Sources

  1. CMS — Final CY 2026 Part D Redesign Program Instructions: 2026 standard deductible cap $615, annual out-of-pocket threshold $2,100, benefit phases and cost-sharing structure. Values verified May 2026.
  2. Medicare.gov — Avoid Late Enrollment Penalties: Part D late enrollment penalty calculation (1% × national base beneficiary premium × uncovered months), national base beneficiary premium $38.99 for 2026, creditable coverage rules.
  3. CMS — 2026 Medicare Parts A & B Premiums and Deductibles: Full 2026 IRMAA surcharge tables for Part B and Part D by income tier and filing status. Tier 5 thresholds ($500K single / $750K MFJ) frozen through 2027.
  4. SSA — Medicare Part D Extra Help: Low Income Subsidy (LIS) eligibility criteria, benefit levels (full vs. partial), how to apply, and automatic enrollment rules for Medicaid/SSI recipients.

Values shown are 2026 standard benefit parameters as set by CMS. Individual plan deductibles, copays, and formularies vary. Use Medicare.gov's Plan Finder to compare actual plans based on your specific drugs, pharmacy, and location. IRMAA surcharge amounts use your 2024 MAGI as reported on your 2024 federal tax return. Amounts are per person — each spouse on Medicare pays separately.

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