Formulary

A formulary is a list of prescription drugs, including generic and brand name, that identifies the drugs that are covered by your Part D or prescription drug plan. Your plan’s formulary is classified into multiple categories known as tiers based on the type of drug and condition or specialty.

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What's Included in the Formulary?

A Plan’s formulary will generally include both brand-name prescription drugs and generic drug coverage, and must include at least two drugs in the most commonly prescribed categories and classes.  While plans must cover at least two drugs per drug category, plans can choose which drugs covered by Part D they will offer.

The formulary might not include your specific drug, but in most cases a similar drug should be available. If you or your prescribing doctor believe that none of the drugs on your plan’s formulary will work for your condition, you can ask your plan provider for an exception.

A Medicare drug plan can make some changes to its drug list during the year if it follows guidelines set by Medicare. Your plan may change its drug list during the year because drug therapies change, new drugs are released, or new medical information becomes available.

Plans offering Medicare drug coverage under Part D may immediately remove drugs from their formularies after the Food and Drug Administration (FDA) considers them unsafe or if their manufacturer removes them from the market. Plans meeting certain requirements also can immediately remove brand name drugs from their formularies and replace them with new generic drugs, or they can change the cost or coverage rules for brand name drugs when adding new generic drugs. If you’re currently taking any of these drugs, you’ll get information about the specific changes made afterwards.

For other changes involving a drug you’re currently taking that will affect you during the year, your plan must do one of these:

  • Give you written notice at least 30 days before the date the change becomes effective.
  • At the time you request a refill, provide written notice of the change and at least a month’s supply under the same plan rules as before the change.

Note

Starting 2019 and beyond, drug plans offering Medicare drug coverage (Part D) that meet certain requirements also can immediately remove brand name drugs from their formularies and replace them with new generic drugs, or they can change the cost or coverage rules for brand name drugs when adding new generic drugs. If you’re taking these drugs, you’ll get information about the specific changes made to generic drug coverage afterwards.

You may need to change the drug you use or pay more for it. You can also ask for an exception. Generally, using drugs on your plan’s formulary will save you money, but if you use a drug that isn’t on your plan’s drug list, you’ll have to pay full price unless you qualify for a formulary exception. All Medicare drug plans have negotiated to get lower prices for the drugs on their drug lists, so using those drugs will generally save you money. 

Generic Drugs

The Food and Drug Administration (FDA) says generic drugs are copies of brand-name drugs and are the same as those brand-name drugs in:

  • dosage form
  • safety
  • strength
  • route of administration
  • quality
  • performance
  • characteristics
  • intended use

Generic drugs use the same active ingredients as brand-name prescription drugs. Generic drug makers must prove to the FDA that their product works the same way as the brand-name prescription drug. In some cases, there may not be a generic drug the same as the brand-name drug you take, but there may be another generic drug that will work as well for you. Talk to your doctor or other prescriber about your generic drug coverage

Tiers

To lower costs, many plans offering prescription drug coverage place drugs into different “tiers” on their formularies. Each plan can divide its tiers in different ways. Each tier costs a different amount. Generally, a drug in a lower tier will cost you less than a drug in a higher tier.

Here’s an example of a Medicare drug plan’s tiers (your plan’s tiers may be different):

  • Tier 1—lowest copayment : most generic prescription drugs
  • Tier 2—medium copayment: preferred, brand-name prescription drugs
  • Tier 3—higher copayment: non-preferred, brand-name prescription drugs
  • Specialty tier—highest copayment: very high cost prescription drugs

In some cases, if your drug is in a higher tier and your prescriber (your doctor or other health care provider who’s legally allowed to write prescriptions) thinks you need that drug instead of a similar drug in a lower tier, you or your prescriber can ask your plan for an exception to get a lower coinsurance or copayment for the drug in the higher tier. Plans can change their formularies at any time. Your plan may notify you of any formulary changes that affect drugs you’re taking.

Medicare drug coverage includes drugs for medication-assisted treatment for opioid use disorders. It also covers drugs like methadone and buprenorphine when prescribed for pain. However, Medicare Part A covers methadone when used to treat an opioid use disorder as an inpatient in a hospital, and Part B now covers methadone when you receive it through an opioid treatment program. Contact the plan for its current formulary, or visit the plan’s website.

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