Keytruda (pembrolizumab) Medicare coverage in 2026.
Keytruda treats Multiple cancers (immunotherapy). Retail cost runs about $18000/month. How Medicare covers it depends on your Part D or Medicare Advantage plan — and the new $2,000 annual out-of-pocket cap makes a huge difference for high-cost drugs.
Keytruda on Medicare — the basics
The 2026 $2,000 Part D cap and you
For 2026, Medicare introduces a brand-new $2,000 annual out-of-pocket cap on covered prescription drugs. This is one of the most significant changes to Medicare in decades.
For a drug like Keytruda retailing at $18000/month ($216000/year), here's what your annual out-of-pocket looks like:
- Without Medicare: $216,000 per year (full retail).
- With Medicare Part D in 2026: Maximum $2,000 out-of-pocket. That is $214,000 per year less than retail.
- Your actual copay depends on your specific Part D plan's tier placement and benefit design.
Office-administered Part B drug for most cancer indications — covered at 80% by Medicare, 20% by Medigap if you have it. Costs are dramatic without Medigap.
Common questions
Does Medicare cover Keytruda?
Yes — Keytruda is covered under Medicare Part D (or Part B for office-administered drugs) for FDA-approved indications including multiple cancers (immunotherapy). Plan formularies and tier placement vary, so the right Part D plan can dramatically lower your cost.
How do I find which Part D plan covers Keytruda cheapest?
Use our free plan finder or call (866) 534-1886 — a licensed advisor checks every plan in your ZIP, runs Keytruda through each formulary, and shows you the lowest-cost option in 14 minutes.
Will the $2,000 cap apply if I'm on multiple expensive drugs?
Yes — the $2,000 cap is a single annual ceiling across all your covered Part D drugs combined. Once you hit $2,000 in OOP, you pay $0 for any additional covered prescriptions for the rest of the year.
What if Keytruda isn't on my plan's formulary?
You can request a coverage exception (your doctor submits paperwork explaining why Keytruda is medically necessary). If denied, you can switch plans at the next AEP (Oct 15 – Dec 7) or during a Special Enrollment Period.
Get the lowest-cost Part D plan for Keytruda.
A licensed advisor runs Keytruda through every Part D plan in your ZIP. Free, 14 min.
Call (866) 534-1886