Research · 11 min read
Why a Plan Can Cover Prescription Drugs and Not Cover Yours
Your plan lists prescription drugs as a covered benefit. Your drug is not on the list. Both facts are true at the same time, and the federal rule that makes them compatible is a counting rule almost nobody has read.
Key takeaways
- Prescription drugs are one of ten benefit categories, and covering the category is defined as a count rather than a list.
- The standard is the greater of one drug in every United States Pharmacopeia category and class, or the number in the state's benchmark plan.
- A plan can meet that standard in full and still not cover the drug you were prescribed.
- The requirement applies to issuers in the individual or small group market — not to large group or self-funded employer plans.
- Each state selects its own benchmark plan, so the floor resolves differently depending on where coverage is issued.
- A pharmacy and therapeutics committee writes the list under rules on specialty mix, voting conflicts, quarterly meetings, and documented rationale.
- For plan years beginning on or after January 2026, that committee must include at least one patient representative.
- The same committee must review and approve every prior authorization criterion, step therapy protocol, and quantity limit applied to a covered drug.
- Where an exception is granted, the plan must count that cost sharing toward your annual limitation on cost sharing.
Answer first: the guarantee is a count, not a list
Prescription drugs are one of ten categories of benefits that certain health plans must cover. That much is what people mean when they say their plan covers prescriptions.
The federal regulation then defines what covering the category actually requires, and this is where the expectation breaks.
A health plan does not provide essential health benefits unless it covers at least the greater of two things. One drug in every United States Pharmacopeia category and class, or the same number of prescription drugs in each category and class as the state's benchmark plan.
Read that twice. The requirement is a minimum number of drugs within each class. It is not a requirement to cover any particular drug.
So a plan can satisfy the rule completely, cover prescription drugs as a category exactly as promised, and still not cover the specific medication you were prescribed. Nothing has gone wrong. That is the rule working as written.
The greater of language matters too. Where a state's benchmark plan holds more drugs in a class than one, the floor rises to that number for plans in that state.
Which plans this rule even applies to
This is the first thing to establish, because the standard does not reach everyone and people assume it does.
The requirement runs to health insurance issuers offering coverage in the individual or small group market. Those are the plans that must include the essential health benefits package.
Large group coverage and self-funded employer plans sit outside that requirement. If your employer funds its own plan, this floor is not what governs your drug benefit.
That produces an outcome people find backwards. A plan bought on your own can carry a federal minimum that a large employer's plan does not have to meet.
It cuts the other way as well. An employer plan is free to be far more generous than the floor, and many are. The point is that the floor is not the thing holding it up.
Work out which kind of coverage you have before you argue from any of this. Your summary plan description and your benefits team settle it quickly.
Why the answer changes at a state line
The second half of the counting rule points at a benchmark plan, and each state picks its own.
The regulation sets out how a state may change its benchmark plan. It may select the benefits another state used, swap in a category from another state's plan, or select a set of benefits outright.
For plan years beginning on or after January 2026, a state may change its benchmark plan by selecting a set of benefits that would become the state's benchmark.
So the federal floor is not one national number. It is a national method that resolves to a different answer depending on where the coverage is issued.
That is the same shape as the state-by-state variation in Medicaid, arriving by a completely different route. One comes from a permission to exclude, this one from a benchmark that each state chooses.
If you move, or if you compare notes with someone in another state, expect the difference and check the benchmark rather than assuming a national rule.
Who actually writes the list, and what the rules say about them
The regulation does not leave the formulary to whoever feels like writing it. It sets standards for the committee that does.
A plan must use a pharmacy and therapeutics committee. Its members have to represent enough clinical specialties to meet enrollees' needs, and a majority must be practicing physicians, practicing pharmacists, and other practicing professionals licensed to prescribe.
Conflict of interest is addressed directly. A member with a conflict involving the issuer or a drug manufacturer is barred from voting on matters where the conflict exists. At least 20 percent of the membership must have no conflict with either.
For plan years beginning on or after January 2026, the committee must include at least one patient representative. The regulation spells out what that person must bring, including relevant experience with patient or community organizations and disclosure of financial interests.
The committee has to meet at least quarterly, and it must keep written documentation of the rationale for every decision about developing or revising the drug list.
The plan also has to submit its formulary drug list to the Exchange, the state, or the federal personnel agency, depending on the plan. The list is a filed document, not an internal memo.
The provision that explains your prior authorization
Buried in the committee's duties is the sentence that connects this standard to what happens at your pharmacy counter.
The committee must review and approve all clinical prior authorization criteria, step therapy protocols, and quantity limit restrictions applied to each covered drug.
So the hurdle in front of your prescription is not an improvisation by a claims system. On a plan subject to this standard, it is a criterion a clinical committee reviewed, approved, and documented a rationale for.
That is worth knowing before you appeal, because it tells you what you are actually arguing with. There is a written criterion, and it was meant to be defensible.
The regulation adds two duties with real teeth. The committee must ensure the drug list covers a range of drugs across a broad distribution of therapeutic categories and classes, treating all disease states, and does not discourage enrollment by any group of enrollees.
It must also ensure appropriate access to drugs included in broadly accepted treatment guidelines and indicative of general best practices at the time. Those are standards a formulary can be measured against rather than vague aspirations.
What the rule gives you when your drug is not on the list
The counting rule creates the gap, and the same regulation names the instrument for it.
A plan providing essential health benefits must have processes letting an enrollee, the enrollee's designee, or the prescriber request access to clinically appropriate drugs the plan does not otherwise cover. That request is an exception.
One consequence is easy to miss and financially significant. Where an exception is granted, the plan must treat the drug as an essential health benefit, which includes counting the cost sharing toward the plan's annual limitation on cost sharing.
The annual limitation on cost sharing is your out-of-pocket maximum. A granted exception does not just get you the drug — it puts what you spend on it inside the ceiling that caps your year.
That is a different outcome from routes that leave your totals untouched, and it is a reason to pursue an exception rather than quietly switching to paying cash.
The mechanics of filing one, and how an exception differs from an appeal, are their own subject. The linked coverage explainer walks through the request itself.
How to use this without overreading it
Establish your market first. Individual or small group coverage is inside this standard, and large group or self-funded coverage is not.
Then find your state's benchmark, because that is what the second half of the counting rule resolves to for plans issued where you live.
Then get the filed formulary and the published criteria for the drug class. The list is a document the plan submitted, so asking for the current version is a routine request.
If a drug you need is not on it, the exception process is the named route, and a granted exception carries the cost-sharing consequence described above.
Keep one limit in mind. A minimum count per class is a floor, not a promise about any specific molecule, and no reading of the rule turns it into one.
What it does give you is a vocabulary. Category and class, benchmark plan, committee rationale, filed formulary, exception request. Those are the words the people on the other side of the phone use.
Sources
- 45 CFR § 156.122 — Prescription drug benefits (the essential health benefits drug standard, the pharmacy and therapeutics committee requirements, and the exception process)The requirement to cover at least the greater of one drug in every United States Pharmacopeia category and class, or the same number in each category and class as the benchmark plan. Also the requirement to submit the formulary drug list to the Exchange, the State or the federal personnel agency. Also the pharmacy and therapeutics committee standards: specialty representation, a majority of practicing prescribers, the voting bar on conflicts, and the 20 percent no-conflict minimum. Also the patient representative for plan years beginning on or after January 2026, the quarterly meetings, and the documented rationale. Also the duty to review and approve all clinical prior authorization criteria, step therapy protocols and quantity limit restrictions. Also the breadth and non-discouragement duties, and the exception process with its consequence for the annual limitation on cost sharing.
- 45 CFR part 156, subpart B — Essential Health Benefits Package (including § 156.110, EHB-benchmark plan standards, and § 156.111, State selection of EHB-benchmark plan)The ten categories of benefits a benchmark plan must cover, of which prescription drugs is one. Also the ways a state may change its EHB-benchmark plan. That includes the provision under which, for plan years beginning on or after January 2026, a state may do so by selecting a set of benefits. This subpart page was fetched and read directly, rather than a section URL being constructed.
- 45 CFR § 147.150 — Coverage of essential health benefitsThat the requirement to include the essential health benefits package applies to a health insurance issuer offering coverage in the individual or small group market. This is the basis for saying the standard does not reach large group or self-funded employer coverage.
Frequently asked questions
My plan says it covers prescription drugs. Why is my drug not covered?
Because covering the category is defined as a count, not a list. The federal regulation sets a floor of the greater of two things. One drug in every United States Pharmacopeia category and class, or the same number of drugs in each category and class as the state's benchmark plan. That is a minimum number of drugs within each class. It never promises a particular medication. A plan can meet the standard fully and still leave your drug off the list, and that outcome is the rule operating normally rather than a mistake.
Does this rule apply to my employer's plan?
Probably not, and that is worth settling before you rely on any of it. The requirement runs to health insurance issuers offering coverage in the individual or small group market, which are the plans that must include the essential health benefits package. Large group coverage and self-funded employer plans sit outside it. If your employer funds its own plan, this federal floor is not what governs your drug benefit, though your plan may well be more generous than the floor anyway. Your summary plan description and your benefits team can tell you which kind of coverage you have.
Why would a plan in another state cover more drugs in the same class?
Because the second half of the counting rule points at a benchmark plan, and each state selects its own. The regulation sets out the ways a state may change that benchmark, including selecting the benefits another state used or selecting a set of benefits outright. For plan years beginning on or after January 2026, a state may change it by selecting a set of benefits that becomes the state's benchmark. The floor is therefore a national method that resolves to a different number depending on where coverage is issued. It is worth checking your own state's benchmark rather than assuming one national answer.
Who decides what goes on the formulary?
A pharmacy and therapeutics committee, working to standards the regulation sets. Members must represent enough clinical specialties to meet enrollees' needs, and a majority must be practicing physicians, pharmacists, and other practicing professionals licensed to prescribe. Anyone with a conflict involving the issuer or a manufacturer is barred from voting where the conflict exists, and at least 20 percent of the membership must have no such conflict. For plan years beginning on or after January 2026, the committee must include at least one patient representative. The committee meets at least quarterly and must document the rationale for every drug-list decision.
Is my prior authorization requirement something the plan just made up?
Not on a plan subject to this standard. The regulation requires the pharmacy and therapeutics committee to review and approve all clinical prior authorization criteria, step therapy protocols, and quantity limit restrictions applied to each covered drug. So there is a written criterion behind the hurdle, reviewed by a clinical committee that must document its reasoning. That is useful to know before you appeal, because it tells you there is a specific criterion to answer rather than a general policy to argue with. Requesting the criteria being applied to your case is a reasonable and ordinary thing to do.
If I get an exception, does what I pay count toward anything?
Yes, and this is the part worth knowing before you give up and pay cash instead. A plan providing essential health benefits must have a process for an enrollee, a designee, or the prescriber to request access to clinically appropriate drugs the plan does not otherwise cover. Where such an exception is granted, the plan must treat that drug as an essential health benefit, including by counting the cost sharing toward the plan's annual limitation on cost sharing. That limitation is your out-of-pocket maximum. So a granted exception both gets you the drug and puts the spending inside the ceiling on your year.