Medicare Part D provides insurance for drugs you purchase at the pharmacy or through mail order.

Part D plans generally only cover drugs listed on the Plan's Formulary which are purchased at a pharmacy in the Plan's network.

Plans must include an exception for drugs which are not excluded by law if:

• Your doctor feels the drug is the only drug that will work for you.
• You take the drug at the time when you sign up for a plan.

You can also request an Exception to get a lower copayment for a drug that is already included in your plan's formulary.

Part D Plans do not cover drugs received in a hospital as an in-patient, or drugs given to you in a doctor's office through a medical professional. These drugs are covered by Medicare Part A and Part B, respectively.

Part D does cover drugs received in an assisted living facility or nursing home.

For more information, see:

• Formularies 101  
• What If A Plan Doesn't Cover A Drug I Am Already Taking Before I Join The Plan?  
• Exceptions If A Drug Is Not On A Formulary   
• Exceptions For A Lower Copayment And Restrictions  

All plans contain a Formulary which is a list of all of the medications available under the plan.

A formulary must cover:

• At least two drugs in each class of drugs used to treat the same medical condition.
• Nearly all drugs used in the following classes:
  • Antidepressants (for depression)
  • Antipsychotics (for mental psychoses)
  • Anticonvulsants
  • Antiretrovirals (for HIV/AIDS)
  • Anticancer

When checking to be sure your drug is on the formulary, contact the carrier covers the exact dosage as well as the form (such as pill, liquid or patch) of each medication that you take.

The following drugs are excluded from Medicare coverage by law: 

• Some drugs used for anti-anxiety treatments. For example: barbiturates and benzodiazepines such as Valium)
• Drugs used for cosmetic uses
• Fertility drugs
• Over-the-counter drugs
• Drugs used with for weight problems

Companies can change formularies whenever they want during the course of a year provided you are given 60 days prior notice. There is an exception: if you have been taking a drug for a while, and do not stop taking it, the plan must cover it even if it changes the formulary.

Plans can also move drugs to a different copay tier at any time during the plan year. You must give you 60 days' notice before doing the plan can make the change. If a change is made, you can request an exception.

Companies must post a current, shortened list of covered drugs on their web site. The list must be updated at least monthly. While companies are not required to confirm coverage of specific drugs over the telephone, they must mail their abridged formulary to anyone who asks for it. Formulary information must indicate if the plan places restrictions on coverage of particular drugs such as prior authorization, step therapy (whether you have to try a less expensive drug first), and dosage limits. Only current members have the right to request a copy of the entire formulary (which is normally sent by mail.)

If you decide that a plan no longer works for you, you can change plans once a year without penalty between November 15 and December 31. The change takes effect January 1 of the next year.

When you first join a new drug plan, you can get a temporary supply of the drug before you leave the pharmacy. Ask the pharmacist to fill the drug as a transition drug. (Although transition policies can vary from plan to plan, every plan has to have a transition policy which applies to all drugs not on the formulary as well as drugs which may require special authorization.)

The minimum a transition policy must coer is a 30 day supply of the medication.

The transition policy can be used at any time within 90 days of joining a new plan

You can only ask for a transitional supply the first time you ask for prescription. This gives your doctor time to ask for an "exception" (approval for the drug) or prescribe a different medication.

If a drug is not on the Formulary, the company will not pay for it unless you request a special exception, and the company agrees to it.

Exceptions are not granted for drugs which are specifically excluded from Medicare coverage by law.

There is a right to an exception for drugs if either of the following occur:

• Your doctor prescribes a drug which is not on your plan's formulary because your doctor believes the drugs on the plan's formulary will not work for you.
• At the time when you sign up for a plan, you are taking a drug which is not on a Formulary.
• You are using a drug covered by your plan, but that drug is removed from your plan's formulary for reasons other than because of safety.

Generally an exception is requested by your doctor, either orally or in writing since he or she has to certify that the drug prescribed is medically necessary and that other drugs are not as effective or may be harmful to you. Plans generally have to approve a request for an exception if it is deemed to be medically appropriate.

When asking for an exception, you can ask for an expedited review. If you do, your plan must respond with in 72 hours of the request for an exception, or within 24 hours or sooner if required for your health.

If the company refuses your request for a special exception, you can appeal. The appeal is to an independent review board. If you are still denied, you can ultimately request judicial review. To learn more about appeals, see: Medicare Advantage: How To Appeal. The procedures are basically the same.

Copayments

You can request an exception to get a lower copayment for a drug which is already included in your Plan's Formulary. Generally this means moving the drug to a lower tier than the one assigned by the Plan.

Note that if you requested an exception to get the drug covered by your Plan, you cannot file a second exception to get the copayment lowered.

Once a copayment is set, the Plan must continue refills at that level for the rest of the calendar year if the doctor continues to prescribe the drug. The Plan can revisit the copayment question each year. You plan must inform you of its policy for the following year in its Annual Notice of Change.

Of course, you have the right to change plans each year as well.

Restrictions

You can also request an exception for other coverage restrictions. For example, you can request that dosage limitations be revised, or step therapy be skipped.