Medicare Donut Hole & Part D Coverage Gap Calculator 2026
Figures last verified against official sources in August 2026.
Quick Answer
Under the Inflation Reduction Act, the old Medicare Part D donut hole (coverage gap) is replaced in 2026 by a hard $2,100 annual out-of-pocket spending cap. Once your true out-of-pocket (TrOOP) spending reaches $2,100, you pay $0 for covered prescription drugs for the rest of the calendar year.
Medicare Part D Out-of-Pocket Cap Calculator 2026
Track your progress toward the 2026 $2,100 Part D out-of-pocket cap under Inflation Reduction Act rules.
We noticed that many seniors dread the start of each year because high prescription costs on brand-name medications used to trigger the "donut hole" penalty gap. We built this free tool because seniors deserve a fast, clear, plain English calculator to track their progress toward the new 2026 federal $2,100 cap — completely private with zero accounts or signups required.
- Seniors taking brand-name or high-tier medications who want to track how quickly they will reach the $2,100 out-of-pocket limit.
- Medicare beneficiaries trying to decide whether to enroll in the Medicare Prescription Payment Plan (M3P) monthly payment program.
- Adult children helping a parent calculate annual out-of-pocket drug costs across Medicare Part D or Medicare Advantage plans.
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How to Use This Tool — Step by Step
- Step 1 — Find your current out-of-pocket drug spending. Look at your latest monthly Explanation of Benefits (EOB) statement from your Medicare Part D prescription plan or Medicare Advantage plan. Find the line marked "True Out-of-Pocket" (TrOOP) year-to-date total.
- Step 2 — Enter your year-to-date spending into the calculator. Type your current dollar total into the field above. If you are planning for a new year starting in January, enter $0.
- Step 3 — Enter your estimated monthly prescription copays. Add up the typical copay amounts you pay each month at the pharmacy counter for all your regular medications and type that monthly average into the tool.
- Step 4 — Click "Calculate My Coverage Status." The calculator calculates your exact milestone month when your copays will drop to $0 for the rest of 2026.
💡 Pro Tip — Spread High Upfront Costs with M3P
If you take expensive medications that would cause you to hit the $2,100 cap early in the year, you can opt into the Medicare Prescription Payment Plan (M3P) through your plan provider. M3P splits your out-of-pocket costs into equal monthly payments across the year without interest or fees. Learn how to opt in at medicare.gov/prescription-payment-plan.
Real-Life Examples — How This Works in Practice
Catherine takes Eliquis ($150/month copay) and Jardiance ($100/month copay), totaling $250 per month in out-of-pocket pharmacy bills.
| Input | Value |
|---|---|
| YTD Out-of-Pocket Spend (January 1) | $0 |
| Monthly Copays | $250 / month |
| Part D Deductible (Plan standard) | $590 |
Catherine reaches her $2,100 cap by August (8 months × $250 = $2,100). For September, October, November, and December, her copays are $0 per month.
Catherine signed up for M3P payment smoothing, dividing her $2,100 total into steady $166.67 monthly bills all year long instead of facing heavy early bills.
Robert was prescribed a specialty oral oncology drug with an initial copay of $1,200 for the first month's fill.
| Input | Value |
|---|---|
| Month 1 Out-of-Pocket Spend | $1,200 |
| Month 2 Out-of-Pocket Spend | $800 (Reaches $2,100 cap) |
Robert reaches his $2,100 cap in February. From March 1 through December 31, he pays $0 for all covered Part D prescriptions.
Robert verified with his pharmacist that his drug was on his plan's formulary (approved list) so every dollar counted toward his $2,100 cap.
These are representative examples based on common situations. Individual results vary based on your specific plan's formulary, deductible structure, and pharmacy network. Always verify your drug costs with CMS (Centers for Medicare & Medicaid Services) or your plan administrator.
Common Mistakes and How to Avoid Them
Assuming Non-Formulary Drugs Count Toward the $2,100 Cap
Many seniors buy medications that are not on their plan's approved drug list (formulary). Out-of-pocket spending on non-formulary drugs does NOT count toward your $2,100 Part D cap.
The fix is to request a Formulary Exception from your plan administrator or ask your doctor to switch you to a covered alternative. Check official rules at medicare.gov drug exceptions guide.
Confusing Part B Infusion Drugs with Part D Outpatient Drugs
Medications administered in a doctor's office or infusion clinic (such as chemotherapy or IV antibiotics) fall under Medicare Part B (Medical Insurance), not Part D. Part B drugs are subject to 20% coinsurance and do NOT count toward the $2,100 Part D cap.
The fix is to check whether your medication is billed under Part B or Part D. Medigap Plan G covers Part B coinsurance. Learn more at medicare.gov Part B drugs coverage.
Forgetting That the $2,100 Out-of-Pocket Cap Resets Annually
The $2,100 out-of-pocket maximum is calculated per calendar year. On January 1 of each year, your out-of-pocket accumulator resets to $0 regardless of when you hit the cap the previous year.
The fix is to plan your prescription refills and consider enrolling in the Medicare Prescription Payment Plan (M3P) at the start of each new plan year at medicare.gov M3P portal.
Official Government Sources Used in This Tool
| Source Name | What We Used It For | Direct Link |
|---|---|---|
| CMS Part D Senior Savings & Out-of-Pocket Cap Guidelines 2026 | Official calculation formula for the $2,100 TrOOP (True Out-of-Pocket) cap and $0 catastrophic phase | CMS 2026 Part D Costs & Caps |
| Social Security Administration — Extra Help Program (LIS) | Income and resource thresholds for low-income drug assistance | SSA Extra Help Program |
| CMS Medicare Prescription Payment Plan (M3P) Standards | Official rules for spreading out-of-pocket drug costs into monthly payments | CMS M3P Official Guidance |
Seniors Audit is an independent educational platform. We are not affiliated with, endorsed by, or connected to any government agency, insurance company, or financial services firm. All calculations use the official formulas and current figures published by the agencies listed above. We do not receive payment for referrals, leads, or any action taken by visitors to this site.
Frequently Asked Questions
Does the Medicare Part D donut hole still exist in 2026?
The traditional "donut hole" coverage gap has been completely eliminated and replaced in 2026 under the Inflation Reduction Act. Instead of paying 25% of brand-name drug costs without limit, your annual out-of-pocket prescription drug spending is capped at $2,100. Once you pay $2,100, your copays for covered Part D drugs drop to $0 for the rest of the year.
What is the 2026 Medicare Part D out-of-pocket cap?
In 2026, the federal maximum out-of-pocket spend for Medicare Part D prescription drugs is $2,100 per person per calendar year. This cap applies whether you have a stand-alone Medicare Part D plan or a Medicare Advantage plan that includes prescription drug coverage (MAPD).
What happens after I reach the $2,100 out-of-pocket cap in 2026?
Once your true out-of-pocket (TrOOP) spending reaches $2,100, you automatically enter the catastrophic coverage phase. In 2026, the catastrophic phase requires $0 copays or coinsurance for all covered Part D medications for the remainder of the calendar year.
What counts toward the $2,100 Part D out-of-pocket limit?
Payments that count toward your $2,100 cap include your annual Part D deductible, your copayments, and your coinsurance payments for covered formulary drugs. Monthly plan premiums and costs for drugs not on your plan's approved formulary do not count toward the $2,100 cap.
What is the Medicare Prescription Payment Plan (M3P)?
The Medicare Prescription Payment Plan (M3P) is a federal program that allows beneficiaries to spread their out-of-pocket prescription drug costs into manageable monthly bill installments throughout the calendar year, rather than paying large upfront amounts at the pharmacy counter in January or February.
Does the $2,100 cap apply to Part B drugs like doctor-administered injections?
No. The $2,100 out-of-pocket cap applies strictly to Medicare Part D outpatient prescription drugs. Medications administered in a doctor's office or outpatient clinic (such as chemotherapy or certain biologic injections) fall under Medicare Part B and are subject to standard Part B 20% coinsurance unless covered by a Medigap plan.
When does the $2,100 Part D out-of-pocket cap reset?
The $2,100 Part D out-of-pocket cap resets every calendar year on January 1st. Your out-of-pocket spending total starts back at $0 at the beginning of each new year.
Can Extra Help (Low-Income Subsidy) help with Part D costs before reaching $2,100?
Yes. If your income and assets are limited, the federal Extra Help program (also known as the Low-Income Subsidy or LIS) pays your Part D plan premiums and reduces your drug copays to small fixed amounts (such as $4.90 for brand-name drugs in 2026) long before you ever reach the $2,100 cap.
Important Terminologies & Abbreviations Explained
The specific out-of-pocket expenses that count toward reaching the annual $2,100 Medicare Part D drug spending cap.
The portion of Medicare that covers outpatient prescription drugs, provided through private insurance plans approved by Medicare.
A free option in Medicare Part D allowing you to pay your out-of-pocket drug costs in capped monthly bills instead of all at once at the pharmacy.
The official list of prescription medications covered by a specific Medicare Part D or Medicare Advantage plan.
A federal program administered by Social Security that helps seniors with limited income pay Part D premiums, deductibles, and copays.
The federal government agency responsible for overseeing and regulating Medicare Part A, Part B, Part C, and Part D programs.
Other Free Tools You May Find Useful
For a complete picture of how Medicare Part D prescription drug coverage works in 2026, visit our Medicare education hub and read our full article on Medicare Part D: how drug coverage works, costs, and the $2,100 cap. To avoid or calculate a drug coverage penalty, use our Part D late enrollment penalty calculator. If high drug costs qualify you for Extra Help, see our Extra Help eligibility screener. For your complete monthly Medicare bill, use our Medicare premium calculator.
About This Educational Estimate: This tool is for educational purposes only. Seniors Audit uses the official formulas published by Centers for Medicare & Medicaid Services (CMS), but results are estimates based on the information you entered. Rules, rates, and eligibility thresholds change annually and vary by individual circumstance.
Always verify your specific result directly with Centers for Medicare & Medicaid Services (CMS) at 1-800-633-4227 or at www.medicare.gov before making enrollment, coverage, or financial decisions.
If you have Medicare questions, a free SHIP counselor in your state can review your specific situation at no cost — find yours at shiphelp.org.
Seniors Audit is independent and not affiliated with any government agency or insurance company. We are not affiliated with, endorsed by, or connected to any government agency, insurance company, or financial services firm. All calculations use the official formulas and current figures published by the agencies listed above. We do not receive payment for referrals, leads, or any action taken by visitors to this site. Last reviewed: August 2026.