Creditable Prescription Drug Coverage Explained
Creditable prescription drug coverage is drug coverage that’s expected to pay, on average, at least as much as Medicare’s standard Part D prescription drug coverage.
What Is Medicare Part D? Prescription Drug Coverage Explained for 2026
Last Modified: 10/05/2026 | Reviewed by Keith Armbrecht (NPN 634015)
Quick Summary
Medicare Part D is insurance that helps cover outpatient prescription drugs.
You can get Part D through a standalone Medicare drug plan when you have Original Medicare or through many Medicare Advantage plans that include drug coverage.
In 2026, no Medicare drug plan can have a deductible higher than $615, and annual out-of-pocket spending for covered Part D drugs is capped at $2,100.
After you reach the $2,100 out-of-pocket threshold, you pay $0 for covered Part D drugs for the rest of the calendar year.
Key Facts
- Part D covers outpatient prescription drugs.
- Plans are offered by private insurers approved by Medicare.
- Standalone Part D works with Original Medicare.
- Most Medicare Advantage plans include Part D.
- Formularies vary by plan.
- Pharmacy networks vary.
- Drug tiers affect cost.
- Prior authorization, step therapy and quantity limits may apply.
- 2026 maximum deductible: $615.
- 2026 covered-drug out-of-pocket cap: $2,100.
- After reaching the cap, you pay $0 for covered Part D drugs for the remainder of the year.
- Higher-income beneficiaries may pay Part D IRMAA.
- Late enrollment penalties can apply without timely or creditable drug coverage.
How Medicare Part D Works
Deductible Stage
If your plan has a deductible, you pay applicable drug costs until you satisfy it.
No Medicare drug plan can have a deductible above:
$615 in 2026
Some plans have a lower deductible or no deductible.
Initial Coverage Stage
After the deductible, Medicare says beneficiaries generally pay 25% coinsurance for covered generic and brand-name drugs under the standard benefit until qualifying out-of-pocket spending reaches:
$2,100 in 2026
Catastrophic Coverage Stage
Once qualifying Part D out-of-pocket spending reaches:
$2,100
you pay:
$0
for covered Part D drugs for the remainder of the calendar year.
What Is a Formulary?
A formulary is the plan’s list of covered medications.
Different Part D plans can place the same drug on different tiers or have different rules.
That’s why you should compare a plan using your actual medications.
Pharmacy Networks Matter
Your cost can differ depending on whether you use:
- Preferred network pharmacy
- Standard network pharmacy
- Mail order
- Out-of-network pharmacy in limited circumstances
Part D Late Enrollment Penalty
If you go 63 consecutive days or more without Part D or other creditable drug coverage after becoming eligible, you may owe a late enrollment penalty.
The penalty can generally continue for as long as you have Part D.
Video Explanation from Keith
Medicare Part D Explained for 2026
Keith's Take
Part D is the Medicare coverage I think people should shop based on data—not brand recognition.
I want your:
exact drugs
dosages
and
preferred pharmacy.
A plan with the lowest premium can be much more expensive if it covers your prescriptions poorly.
And don’t assume the plan that’s best this year will be best next year.
Drug formularies and costs can change.
Keith Armbrecht
Medicare on Video
Frequently Asked Questions About Part D
Q. What does Part D cover?
A. Outpatient prescription medications listed on the plan's formulary, subject to plan rules.
Q. How much is the 2026 deductible?
A. No plan can have a deductible higher than $615.
Q. What's the 2026 out-of-pocket limit?
A. $2,100 for covered Part D drugs.
Q. What happens after $2,100?
A. You generally pay $0 for covered Part D drugs for the rest of the calendar year.
Q. Does Plan G include drug coverage?
A. No.
Q. Does Medicare Advantage include Part D?
A. Most Medicare Advantage plans include prescription drug coverage.
Q. Can I get a Part D penalty?
A. Yes, if you go too long without Part D or other creditable prescription coverage.
Q. Should I review my plan every year?
A. Yes.
Official Government Sources
Explore Related Guides
Medicare Part D Tiers, Copays and Coinsurance Explained
Medicare drug plans commonly divide covered medications into tiers, with lower-tier drugs generally costing less and higher-tier drugs generally costing more.
