Formulary
A formulary is your health insurance plan’s list of covered prescription drugs. It shows which medicines your coverage helps pay for and how much you may pay for each one. The list may include both generic and brand-name drugs. Checking the formulary can help you see if your medicine is covered before you fill a prescription.
Last updated: October, 2026
Key Takeaways
- A formulary is your insurance plan’s list of covered prescription drugs.
- Not every prescription drug is on every formulary.
- Drugs on the list are often grouped into cost levels called tiers.
- Your out-of-pocket cost can be different based on the drug tier.
- Checking the formulary can help you avoid surprise pharmacy costs.
What is a Formulary?
A formulary is the list of prescription drugs your health insurance plan covers, sometimes called a prescription drug list (PDL). It helps show which medicines are included under your pharmacy benefits. A formulary may include both brand-name drugs and generic drugs.
It also often places drugs into tiers, which are groups that affect what you pay. For example:
- Tier 1 (Generic drugs): Lowest cost, often with the lowest copay (for example, common blood pressure medications)
- Tier 2 (Preferred brand-name drugs): Moderate cost, with a higher copay than generics (for example, commonly used brand-name medications)
- Tier 3 (Non-preferred brand-name drugs): Higher cost, often with higher copays or coinsurance (for example, brand-name drugs without preferred status)
- Specialty tier: Highest cost, often for complex or specialty medications (for example, treatments for chronic or rare conditions)
Some drugs may also have rules, like prior approval, quantity limits, or step therapy. Checking the formulary can help you see whether your medicine is covered before you go to the pharmacy.
What Are the Types of Formularies?
Health insurance plans can use different types of formularies to manage which drugs are covered and how they are accessed:
- Open formulary: Covers a wide range of medications, including both brand-name and generic drugs, often with fewer restrictions
- Closed formulary: Covers only specific drugs on the list, meaning some medications may not be covered at all
- Preferred formulary: Highlights certain drugs as preferred options, usually at a lower cost than non-preferred drugs
- Specialty formulary: Focuses on high-cost or complex medications, often with additional rules like prior authorization
How This Shows Up in Real Life
For example, your doctor prescribes a certain medication for high blood pressure. You check your plan’s formulary and see that the generic version is covered on a lower tier. That means you may pay less for the generic drug than for the brand-name version.
How a Formulary Affects What You Pay
A formulary can have a big effect on your prescription drug costs. Drugs on lower tiers usually have lower copays or coinsurance. Drugs on higher tiers may cost more out of pocket.
If your medicine is not on the formulary, you may have to pay the full cost or ask your doctor about another option. That is why it helps to check the formulary when you compare plans or fill a new prescription.
Where to Find This in Your Plan Details
To check your formulary and understand how your prescription drugs are covered, you can look at:
- Your Insurance plan's Pharmacy Resources or formulary
- Your Summary of Benefits and Coverage (SBC)
- Your Schedule of Benefits
- Your member handbook or policy documents
- Your Ambetter Health online member account
You may also find a separate prescription drug list in your plan materials. These resources can help you check drug tiers, coverage rules, and pharmacy costs.
How This Changes Across Marketplace Plans
Formularies can be different across Marketplace health insurance plans. Even if two plans cover the same type of care, they may not cover the same drugs in the same way. One plan may list certain medicines on its formulary while another plan may not include them. Plans can also place the same drug in different tiers or apply different coverage rules.
- One plan’s formulary can be very different from another plan’s.
- The same drug may cost more under a different plan.
- Some plans have extra rules before they cover certain drugs.
- It helps to check both the drug list and the pharmacy network before you pick a plan.
| Plan Feature | How It Can Be Different | What It Means for You |
|---|---|---|
| Covered Drugs | One insurance plan may cover a drug that another does not | Your medicine may be covered under one insurance plan but not another |
| Drug Tiers | Insurance plans can place the same drug in different tiers | Your copay or coinsurance can change |
| Coverage Rules | Some insurance plans may require prior approval, step therapy, or quantity limits | You may need to meet extra rules before the drug is covered |
| Pharmacy Network | Insurance plans can work with different pharmacies | Your cost may be lower when you use an in-network pharmacy |
FAQs About Formulary
Usually, yes. Many plans use these terms to mean the same thing. Both refer to the list of prescription drugs your insurance plan covers under its pharmacy benefits.
It means the plan may not cover that drug. You may need to pay the full cost or ask your doctor if there is a covered option. In some cases, your doctor may also be able to request an exception from the plan.
Drug tiers are groups that affect how much you pay for a medicine. Lower tiers usually cost less, while higher tiers usually cost more. The tier can also affect whether you pay a copay or coinsurance.
Yes. A formulary can include both types of drugs. Generic drugs usually cost less, but coverage and cost levels depend on the plan’s drug tiers.
Checking the formulary can help you see whether your medicines are covered and what they may cost. This can help you choose a plan that better fits your health needs and budget before you enroll.
Have questions? Let’s walk through how this works with your plan.
Already covered? Your benefits vary by plan and location. Limitations and exclusions may apply. Contact Ambetter Health or call Member Services at the number on the back of your Member ID Card for answers specific to your coverage.
Not yet a member? Our licensed agents are ready to help you find the perfect plan. Call 855-680-3270 (TTY: 711), Monday-Friday 8 a.m. to 9 p.m. ET, to discuss your health insurance options.
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