Websites for insurance providers often contain a drug formulary list specific to their plans, according to HAP and United Healthcare. A formulary list specifies the prescription medications that a health care plan covers. Insurers often offer different plans that cover different drugs, and plans also vary by state.
Some companies such as United Healthcare give their members the option of looking up particular drugs or going through the page for their plan to see if certain drugs are included. In many cases, the formulary lists vary by year, so it's important to look at the correct year. These lists are generally available in PDF format as of 2015, notes HAP.