It is important to understand the basics of drug formularies, offered by different insurance companies. The formulary lists the drugs by tiers or levels, with tier 1 being the least expensive and the higher tiers being more expensive. Often, your health care provider will start at level 1. Your health care provider will have to have a reason to get a specific drug at an higher tier authorized.it is wise to have an approximate annamount that you will be paying for drugs if you take many drugs. Medicare has a cap of $2000 this year,$2100 for next year. The link below reviews the basics : https://www.goodrx.com/insurance/health-insurance/medication-formulary