Formulary

A formulary is a health plan’s list of the prescription drugs it covers, usually sorted into tiers that set what you pay for each one. A formulary drug is simply a drug on that list. A non-formulary drug is not covered at all, though an exception can be requested.

On the list means covered, on conditions. The tier sets your share: lower tiers, mostly generics, cost least; higher tiers, brand-name and specialty drugs, cost most. A drug on the list can still need prior authorization, carry a quantity limit, or sit behind step therapy, the rule that a cheaper drug must be tried first. Each plan builds its own list and sets its own tiers, which is why the same drug at the same dose can cost differently in two plans with the same premium. And the lists are rewritten every year, so a drug can move tiers at renewal.

The part people get wrong is the word “covered”. At the counter, “not covered” can mean five different things: prior authorization needed, a step therapy requirement, a quantity limit, a drug genuinely off the list, or a billing error. Each has a different fix. For a drug off the list, the fix is a formulary exception request, and the prescriber’s supporting statement matters. For step therapy, the exception exists for people who have already tried the required drug, and it turns on which drug, roughly when, and what happened.

You meet the formulary in two places. The first is the plan’s drug list when you choose or renew a plan: look up each medication by name and dose and note the tier. The second is the pharmacy counter, when a claim is rejected. Ask the pharmacist to read you the rejection reason, because it tells you which of the five problems you have, and three of the five are fixed by the prescriber’s office, not by you and not by the plan’s consumer line.

In New York: which list applies depends on your coverage. On mainstream Medicaid managed care, a Health and Recovery Plan or an HIV special needs plan, the pharmacy benefit has run since April 1, 2023 through NYRx, the state’s own program: one statewide drug list and one set of prior authorization rules. Your plan card stays the same, changing plans no longer changes your drug list, and a denial reason is the same in Buffalo as in Brooklyn. Managed long-term care (including PACE and MAP), the Essential Plan and Child Health Plus kept pharmacy inside the plan, so each of those plans still has its own list. On plans the state regulates, prescription insulin has carried no cost sharing since January 1, 2025: no deductible, no copay, no coinsurance, high-deductible plans included. The rule does not reach self-funded employer plans, individual catastrophic plans or Medicare Part D. A commercial denial that survives the internal appeal goes to an external appeal through the Department of Financial Services; a Medicaid denial goes to the plan’s appeal, then a fair hearing. Medicare Part D runs on its own federal track. Its plans rewrite their lists every year, which is why yours needs rechecking every fall, and EPIC, the state program for residents 65 and older, sits behind a Part D plan and pays down what you owe at the counter.

• Before you enroll or renew, look up every medication by name and dose and note its tier. On Medicare Part D, do it again every fall. What the fall season decides.
• At the counter, get the rejection reason and ask for an emergency or temporary supply while it is sorted out.
• Call the prescriber with the rejection wording and the dates of what you already tried. Only the prescriber can submit prior authorization or a step therapy exception, and asking whether a drug on the list would work sometimes settles it the same day.
• If the denial stands, appeal on your coverage’s track. On Medicaid, ask for aid continuing within about 10 days if you already take the drug. The order of operations.
• Charged for insulin on a state-regulated plan? Ask the pharmacy to re-run it, then write to the plan. What to say.

Also called: drug list, preferred drug list. Full guide: Prescription costs in New York. Reference: Formulary on Wikipedia — general definition, not New York specifics.