What are tier 1, 2, 3, 4 and 5 drugs?

Understanding Drug Tiers in Your Health Plan

When you open your health insurance plan’s formulary—the list of covered medications—you might notice drugs grouped into numbered categories. These are called tiers, and they play a big role in how much you’ll pay out of pocket. Most plans use a 5-tier system, designed to encourage cost-effective choices while still offering access to necessary medications.

Tier 1 typically includes preferred generic drugs—the lowest-cost options. These are generics your insurance company favors because they’re both effective and economical. Moving up, Tier 2 covers nonpreferred generics and some slightly more expensive generics. While still affordable, they cost a bit more than Tier 1 drugs.

Tier 3 is where brand-name medications enter the picture. These are often preferred brand-name drugs, meaning your insurer has negotiated lower prices for them, along with some higher-cost generic options. You’ll pay more here than for generics, but less than for nonpreferred brands.

Tier 4 includes nonpreferred brand-name drugs and the most expensive generics. These medications usually have higher copays because either they’re not on the preferred list or generics are available but not selected. Insurers use this tier to steer patients toward more affordable alternatives when possible.

Some plans include a Tier 5 for specialty medications—high-cost drugs used to treat complex conditions like cancer or multiple sclerosis. These often require special handling, administration, or monitoring, justifying their separate classification.

Knowing your drug’s tier helps you anticipate costs and talk to your doctor about alternatives. Always check your plan’s formulary or speak with your pharmacist—small changes in tier can mean big differences in price.