What to Do If a Drug Is Not Covered or Costs More Than Expected

A drug surprise can come from the formulary, the tier, the pharmacy, a deductible, prior authorization, step therapy, or a plan change.

A drug surprise at the pharmacy has seven common causes. Some are about whether the drug is covered at all. Some are about how much you owe. Identifying which cause applies tells you what to do next — confirm the formulary, switch pharmacies, ask the prescriber about an alternative, request prior authorization, request an exception, or wait until the deductible has been met. Do not assume the plan is wrong, and do not assume the plan is right. Confirm the rule, then act.

Short answer: Drug surprises have seven common causes. Identify the cause first. Most are resolved by confirming the formulary, switching pharmacies, asking the prescriber about a covered alternative, or requesting a coverage exception. Switching plans is almost never the fastest fix mid-year.

How this applies to you

If you are at the pharmacy right now and the cost is wrong. Ask the pharmacist what the system is showing — covered or not covered, what tier, whether prior authorization is required, whether step therapy applies, whether the plan deductible is still in play. Write down the answer. Do not pay full price yet if a lower-cost path exists.

If the pharmacy says the drug is not covered. Ask which plan they ran it under and confirm it matches your current plan. Ask if the rejection mentions prior authorization, step therapy, or a quantity limit. These are different from “not covered” and have different fixes.

If the cost looks much higher than you expected. Confirm the drug name, dosage, pharmacy, and your current plan. The same drug at the same dose can cost very different amounts at different pharmacies under the same plan. Preferred pharmacies often have meaningfully lower copays.

If you have not yet started the drug. Before you fill it, look up the drug on your plan’s formulary, confirm the pharmacy is preferred, and ask the prescriber whether a covered alternative would work equally well for you.

The seven common causes

Cause 1 — Drug is not on the formulary

Every Part D plan and every Medicare Advantage plan with drug coverage publishes a formulary — the list of drugs the plan covers. If your drug is not on the formulary, the plan will reject the claim or ask for an exception.

What to do: Confirm by looking up your plan’s current formulary online or by calling the plan. If the drug is genuinely not on the formulary, options include:

• Asking the prescriber if a similar drug on the formulary would work for you
• Requesting a formulary exception (the prescriber submits a written request)
• Paying out of pocket while you decide

Cause 2 — Drug is on the formulary but on a higher tier than expected

Formulary tiers determine your cost share. A tier 1 generic typically has a low copay; tier 4 or 5 specialty drugs typically have coinsurance (a percentage of the drug cost), which can be much higher.

What to do: Confirm the tier. Ask the prescriber whether a lower-tier alternative exists. If the higher-tier drug is medically necessary for you specifically, the prescriber can request a tiering exception — a formal request that the plan treat the drug as if it were on a lower tier.

Cause 3 — Pharmacy is not preferred under your plan

Plans have networks of pharmacies. Many plans designate some as preferred and others as standard. Preferred pharmacies have lower cost share for the same drug. Some plans only fully cover certain drugs at preferred pharmacies.

What to do: Confirm your pharmacy’s status. If it is standard, ask the plan which preferred pharmacies are nearby or whether mail-order is an option. Switching pharmacies can change your cost meaningfully without changing anything else.

Cause 4 — You have not yet met the plan deductible

Some Part D plans and Medicare Advantage drug coverage have an annual deductible. Until you have spent the deductible amount out of pocket on covered drugs, you pay the full negotiated price (which is often lower than the cash price, but still higher than your post-deductible copay).

What to do: Confirm with the plan whether the deductible applies to this drug and how much of it is left. If the deductible is the cause, the cost will drop to your copay or coinsurance amount once the deductible is met.

Cause 5 — Prior authorization required

Some drugs require the prescriber to submit a prior authorization request before the plan will cover them. Until the request is approved, the pharmacy will not be able to dispense the drug under your plan.

What to do: Ask the pharmacy whether prior authorization is the cause. If yes, contact the prescriber’s office and ask them to submit the prior authorization. Standard requests typically take a few business days; expedited requests are available for urgent medical situations.

Cause 6 — Step therapy required

Step therapy means the plan requires you to try (and fail or be unable to tolerate) one or more lower-cost drugs before it will cover the requested drug. This applies most often to newer or higher-cost medications where lower-cost alternatives exist.

What to do: Ask the prescriber whether step therapy applies and what the plan’s required step is. Two paths forward — start with the required drug, or request an exception based on medical necessity if the required drug is not appropriate for you. The prescriber submits the exception request.

Cause 7 — Quantity limit or plan change

Some drugs have quantity limits — a maximum amount the plan will cover in a given period. Or the plan may have changed its rules mid-year (rare but possible — see your Annual Notice of Change each fall for upcoming-year changes).

What to do: Confirm whether a quantity limit applies. If yes, the prescriber can request a quantity limit exception when the medical need is greater than the standard limit. If a plan change is the cause, you may be in a window where the previous rule still applies — confirm with the plan.

Quick triage table

When the prescriber should be the first call

Causes 5, 6, and 7 — prior authorization, step therapy, quantity limits — require action from the prescriber, not from you. The prescriber’s office is set up to handle these requests. Call the prescriber’s office directly and ask them to start the request. Confirm a timeframe for follow-up.

When the plan should be the first call

Causes 1, 2, 3, and 4 — formulary, tier, pharmacy, deductible — are about how the plan is processing your drug. The plan can confirm the rule and walk you through the next step.

What “exception” actually means

A coverage exception is a formal request that the plan cover a drug differently than its standard rules — covering a non-formulary drug, treating a drug as a lower tier, lifting a quantity limit, or waiving step therapy. Exceptions are filed by the prescriber on your behalf, often with supporting clinical information.

Exception requests have specific timeframes set by federal regulation. The plan must respond within a defined window. If the request is denied, you have appeal rights — see Medicare Appeal Timeframes Reference for the general calendar, and read your denial letter for your specific deadline.

What people get wrong about drug surprises

The most common mistake is paying full retail price at the pharmacy before identifying the cause. The reader assumes “not covered” means “I have to pay cash” when often the issue is fixable in one call.

The second most common mistake is asking the wrong source. A pharmacy can tell you what the system is showing. They cannot file a prior authorization. The prescriber can file a prior authorization. They cannot tell you why the pharmacy is not preferred. The plan can confirm both.

The third most common mistake is waiting until Medicare Open Enrollment to address a drug surprise. If a drug you take regularly is not covered, exceptions and alternatives are usually faster than waiting months for the next enrollment window.

A short script for the pharmacy

“Can you tell me exactly what message you are seeing? Is it ‘not covered,’ ‘prior authorization required,’ ‘step therapy,’ ‘quantity limit,’ or something else? Can you also confirm what plan you ran this under and whether this pharmacy is preferred for that plan?”

A short script for the plan

“Hello, I am calling about a prescription drug issue. My member ID is [number]. My doctor prescribed [drug name and dose]. The pharmacy at [pharmacy name] told me [exact message]. Can you confirm whether this drug is on the formulary, what tier it is, whether prior authorization or step therapy is required, and whether this pharmacy is preferred under my plan?”

Write down the answers. Get a reference number for the call.