Medicare Part D Coverage Gap Budget

Project how much cash you should set aside for Medicare Part D prescriptions once you move through the deductible, initial coverage phase, donut hole, and catastrophic protection. Provide your expected annual retail drug cost along with the plan’s limits to reveal estimated out-of-pocket exposure for the year.

Sum all medications at their negotiated retail price before insurance.
The plan's initial coverage limit before the donut hole begins.
Enter the TrOOP dollar amount where catastrophic coverage activates.
Defaults to $0. Include the plan deductible you must pay before coinsurance applies.
Defaults to 25%. Enter the percentage you pay during the initial coverage phase.
Defaults to 5%. Set to 0 for 2025+ plans with capped catastrophic out-of-pocket.

Estimates only—verify plan-specific stages, manufacturer assistance rules, and CMS thresholds with your carrier before making enrollment or budgeting decisions.

Examples

  • $12,000 in drugs, $5,030 initial limit, $8,000 catastrophic, $545 deductible, default coinsurance ⇒ $2,608.75 USD out-of-pocket
  • $6,800 in drugs, $5,030 initial limit, $8,000 catastrophic, no deductible, 22% initial coinsurance, catastrophic 0% ⇒ $1,549.10 USD out-of-pocket

FAQ

Does the calculator include manufacturer discounts in TrOOP?

Manufacturer discounts count toward the TrOOP threshold but do not change your coinsurance. Enter the retail cost so the donut-hole estimate stays aligned with CMS accounting.

How do I handle plans with tiered copays instead of coinsurance?

Convert the copay into an effective percentage by dividing the copay by the drug’s retail price, or run separate scenarios for each tier and sum the outputs.

Can I model the 2025 $2,000 cap?

Yes. Set the catastrophic coinsurance to 0% and the threshold to $2,000 to approximate the new out-of-pocket ceiling, then rerun the calculator with your 2025 formulary costs.

Additional Information

  • Initial coverage coinsurance defaults to 25%, matching many standard Part D plans before the gap.
  • Gap spending applies a 25% coinsurance to the slice of retail costs that fall inside the coverage gap.
  • Catastrophic coinsurance defaults to 5%; set it to 0 for 2025 plan designs with fully capped out-of-pocket after TrOOP.

Related calculators