Formulary and Exclusions

A drug formulary is a list of FDA-approved generic and brand-name prescription drugs and supplies covered by Express Scripts, Inc. (ESI). ESI places covered drugs into three levels: preferred generic, preferred brand or non-preferred.

Preferred drugs are covered at a lower cost to you. Non-preferred drugs are covered, but you will pay more than if you choose preferred generic or preferred brand drugs. If your health care provider prescribes a non-preferred drug, discuss preferred alternative options with your provider.

There are some drugs that are not covered. These drugs have a covered alternative option that can be discussed with your provider. In most cases, if you fill a prescription for one of these drugs, you will pay the full retail price. Your provider may request a clinical exception to cover the drug by calling Express Scripts’ Prior Authorization Line. Approved exceptions are covered as a non-preferred drug.

ESI’s preferred formulary list is available here (2025 Formulary List with Exclusions | 2024 Formulary List with Exclusions) or by contacting ESI, and can change throughout the year. If you have a question about a drug you take, please call ESI at 800-797-5754.

Brand-for-Generic Substitution Program
The plan will prefer select brand drugs, as decided by ESI, and not cover their higher net-cost generic equivalent. Members will pay the generic copayment for the brand in this program.

Covered 100%
There are certain medications that MCHCP will cover at 100%, when accompanied by a prescription and filled at a network pharmacy. See Preventive Services for more information.