You can find a Medicare Part D plan that’s right for you if you shop carefully. It’s easy to focus only on your premium amount, but there are other things to look at when you choose a prescription drug plan. For example, you should also look at your estimated out-of-pocket costs. This amount will depend on the plan’s cost sharing (deductibles, copays and coinsurance) and the plan’s prices for the drugs you take.

Find out if the plan offers a mail-order option, which can reduce your Medicare copay costs, while offering the convenience of getting your drugs delivered to your door.

Check the plan’s formulary to see if it covers the drugs you take. A formulary is the list of the drugs that the plan covers. Each Medicare Part D plan has its own formulary and costs vary by plan.

Drug Groupings                                           Medicare Part D Formulary

All FDA-approved drugs are grouped by what the drugs do—fight infection, lower blood pressure, etc. Drugs in the same group treat the same condition. Plans build their specific formularies by selecting drugs from these groups.

Before you choose a plan, look at the plan’s formulary to see if it covers the drugs you take. If it doesn’t, another plan that does cover the drugs is probably a better fit.

Tiered Medicare formulary

Many drug plans have what's called a "tiered formulary." That means the plan divides drugs in its formulary into groups, called "tiers." Generally, the lower the tier, the lower your copay costs. For example, a generic version of a drug in Tier 1 may have a lower copay than a brand-name version of the same drug in Tier 3.

Step Therapy

Some plans with tiered formularies have special requirements for certain drugs. One of these requirements is called “step therapy.” With step therapy, you must first try a less-expensive drug to see if it works for you. You may “step up” to a more expensive drug that treats the same condition only if you and your doctor can show that the less expensive drug didn’t work for you.

What if your drugs aren’t on the formulary?

Sometimes you can’t find a plan that includes all of your drugs. Or your plan may change its formulary to exclude one of your drugs. A plan can change its formulary after giving you notice. But a change that excludes a drug you are already taking usually will not affect you until the next year.

If your drugs aren’t on the formulary, talk to your doctor. There may be another drug on the formulary similar to your current drug. Or your doctor may be able to ask your plan to make an exception for you. Your doctor will need to show proof that no drug on the formulary works for you.