Your pharmacy says your Medicare drug plan won't cover a prescription, or it wants far more than you can pay. You don't have to just accept that. You can file a formal request called a coverage determination, and once you do, the plan is on a federal clock to answer. Here's how the request works and how fast the plan has to respond.
In This Guide
- Key Takeaways
- What a Medicare Part D Coverage Determination Is
- How to Ask for a Medicare Part D Coverage Determination
- What Deadlines the Plan Must Meet
- When You Can Ask for a Fast Decision
- What If the Answer Is Still No
- Frequently Asked Questions
- Learn More
What a Medicare Part D Coverage Determination Is
A coverage determination is the first formal decision your drug plan makes about whether, and how, it will cover a specific drug for you. It's the official way to say "I think you got this wrong, please decide in writing." According to the Centers for Medicare & Medicaid Services (CMS), it covers a few different asks.
The plainest one is a request for a drug that has strings attached: your plan covers it, but only after prior authorization, or only up to a quantity limit, or only after you've tried a cheaper drug first (step therapy). You're asking the plan to approve it for you.
Then there are two kinds of exception requests, and they're the ones people reach for most when a drug gets denied:
- A formulary exception asks the plan to cover a drug that isn't on its formulary, the list of drugs it normally pays for.
- A tiering exception asks the plan to charge you a lower, cheaper cost-sharing tier for a drug it does cover.
Both exception types lean on one thing: your prescriber's medical reasoning for why you need this specific drug. That statement is what sets the plan's decision clock ticking.
How to Ask for a Medicare Part D Coverage Determination
Good news on this one: you're not the only person who can file. You can request a coverage determination yourself, or your appointed representative can, or your prescribing doctor (or other prescriber) can do it on your behalf. For an exception, having your prescriber drive it usually helps, because the plan needs their supporting statement anyway.Centers for Medicare & Medicaid Services. (n.d.). CMS — Part D Coverage Determinations. cms.gov. Retrieved Jul 10, 2026, from https://www.cms.gov/medicare/appeals-grievances/prescription-drug/coverage-determinations
That supporting statement is the heart of an exception request. It's your prescriber explaining, in medical terms, why the formulary drug won't work for you, or why you need the non-preferred drug. You can file the request first and have the statement follow, but the plan's decision clock doesn't start until that statement arrives.
You can make the request orally or in writing (many plans have a form on their website), and your plan's coverage documents list exactly where to send it. If you're not sure, the phone number on the back of your plan member card gets you to the coverage-determination department.
What Deadlines the Plan Must Meet
Here's where it pays to know the rules, because your plan is on a federally set clock. The timeframes come straight from the Code of Federal Regulations (42 CFR 423.568 and 423.572), and CMS spells them out on its coverage-determinations page.Centers for Medicare & Medicaid Services. (n.d.). CMS — Part D Coverage Determinations. cms.gov. Retrieved Jul 10, 2026, from https://www.cms.gov/medicare/appeals-grievances/prescription-drug/coverage-determinations
For a straightforward request for a drug (not an exception), the plan must give you notice of its decision no later than 72 hours after it receives a standard request, or 24 hours for an expedited one.Centers for Medicare & Medicaid Services. (n.d.). CMS — Part D Coverage Determinations. cms.gov. Retrieved Jul 10, 2026, from https://www.cms.gov/medicare/appeals-grievances/prescription-drug/coverage-determinations Exception requests run on the same 72-hour and 24-hour deadlines, with one big difference: the clock doesn't start when you file. It starts when the plan receives your prescriber's supporting statement.
| Type of request | Deadline to decide | When the clock starts |
|---|---|---|
| Standard request for a drug | 72 hours | When the plan receives the request |
| Expedited (fast) request | 24 hours | When the plan receives the request |
| Exception (formulary or tiering) | 72 hours standard, or 24 hours expedited | When the plan receives your prescriber's supporting statement (or 14 days after the request if none arrives) |
| Standard payment (reimbursement) | 14 calendar days | When the plan receives the request |
That 14-day line on the exception row matters. If your prescriber never sends the supporting statement, the plan doesn't get to sit on your request forever. After 14 calendar days from the exceptions request, its 72-hour (or 24-hour) clock starts anyway, so it still has to decide.Centers for Medicare & Medicaid Services. (n.d.). CMS — Part D Coverage Determinations. cms.gov. Retrieved Jul 10, 2026, from https://www.cms.gov/medicare/appeals-grievances/prescription-drug/coverage-determinations
And if you already paid for the drug out of pocket and want the plan to reimburse you, that's a standard payment request. The plan has 14 calendar days to decide a standard payment (reimbursement) request.Centers for Medicare & Medicaid Services. (n.d.). CMS — Part D Coverage Determinations. cms.gov. Retrieved Jul 10, 2026, from https://www.cms.gov/medicare/appeals-grievances/prescription-drug/coverage-determinations
When You Can Ask for a Fast Decision
The 24-hour expedited track isn't automatic, and it isn't for convenience. You (or your prescriber) can ask for it when waiting the standard 72 hours could seriously jeopardize your life, your health, or your ability to regain maximum function.Centers for Medicare & Medicaid Services. (n.d.). CMS — Part D Coverage Determinations. cms.gov. Retrieved Jul 10, 2026, from https://www.cms.gov/medicare/appeals-grievances/prescription-drug/coverage-determinations
Here's how it plays out in practice. If your prescriber tells the plan that a standard wait would put your health at that kind of risk, the plan must grant the fast track. According to Medicare, a plan can also decide on its own that your request qualifies. If you ask for expedited handling without your prescriber's backing and the plan doesn't grant it, your request is still decided, just on the standard 72-hour timeline instead. So when speed matters, loop your prescriber in early.
What If the Answer Is Still No
A coverage determination is only round one. If the plan denies your request, you have the right to appeal, and the appeal is a separate process with its own deadlines, called a redetermination. That's the next step, not the end of the road, and plenty of denials get overturned on appeal.
We walk through all five appeal levels, the deadlines, and the fast track for urgent cases in our guide on how to appeal a Medicare denial. The short version: read the denial notice the plan sends you, because it tells you exactly how long you have to appeal and where to send it.
Frequently Asked Questions
How long does a Part D coverage determination take?
For a standard request, your plan must decide within 72 hours. For an expedited (fast) request, it's 24 hours. For an exception request, those same clocks don't start until the plan receives your prescriber's supporting statement, or 14 calendar days after the request if no statement arrives.
What's the difference between a formulary exception and a tiering exception?
A formulary exception asks the plan to cover a drug that isn't on its drug list at all. A tiering exception asks the plan to charge you a lower, cheaper cost-sharing tier for a drug it already covers. Both need your prescriber's supporting statement explaining the medical reason.
Can my doctor request the coverage determination for me?
Yes. You, your appointed representative, or your prescribing doctor can file the request. For an exception, your prescriber's involvement is especially useful, since the plan needs their supporting statement before its decision clock even starts.
The plan already made me pay full price. Can I get that money back?
You can file a standard payment request asking the plan to reimburse you for a covered drug you paid for out of pocket. The plan has 14 calendar days to decide that request.
What happens if the plan says no?
You can appeal. The appeal, called a redetermination, is a separate process with its own timeline. Your denial notice tells you how long you have to file and where to send it, and many denials are overturned on appeal.
Learn More
Find personalized help asking your Medicare drug plan to cover a denied prescription at brevy.com.
The information on Brevy.com is for educational purposes only and is not a substitute for professional legal, financial, or medical advice. Rules vary by state and program and change frequently. Always verify with the relevant agency or a qualified professional. Brevy is not a law firm, financial advisor, or healthcare provider.