By Patricia Barry

Copyright © 2015 AARP. All rights reserved.

Presenting the correct Medicare/Medicaid card when you show up at a doctor’s office or hospital is critically important. That’s not just because it proves you have health insurance. It’s mainly because the card tells your provider whom to bill.

For example, if you’re in a Medicare Advantage HMO plan and by mistake show your regular Medicare card rather than your HMO plan membership card, the provider will bill Medicare and not the plan. Medicare will then deny your claim, and you or the provider will have a lot of hassle sorting it out. So it pays (no pun intended) to know your cards and how to use them appropriately.

Your Medicare ID card

Printed on plain white thick paper, your Medicare ID carries the circular logo of the Department of Health and Human Services and three red, white, and blue stripes at the top. The white stripe has “Medicare Health Insurance” emblazoned across it. The front of the card indicates your name, gender, Medicare ID number, the coverage you’re entitled to (Part A, Part B, or both) and the date(s) that coverage begins. It also shows the phone number of Medicare’s help line.

Use this card to obtain medical services if you receive your health benefits through traditional Medicare. You may need to show other cards as well if you also have Medigap supplemental insurance or benefits from a retiree plan or other source that acts as a supplement to Medicare.

You’ll notice that your Medicare ID has one or two additional letters or numbers following the digits. They identify what kind of beneficiary you are for Social Security’s administrative purposes. (For example, a T typically indicates that you are not yet receiving Social Security retirement benefits.) They don’t affect you.

Your Medicaid ID card

If you’re entitled to both Medicaid and Medicare services or the benefits of a Medicare Savings Program, you’ll receive a Medicaid ID card from your state. Because Medicaid is run by the states, each card has a different look and color. It carries your name, gender, and Medicaid ID number, and the name of your state or its abbreviation (for example, KY for Kentucky). It may also say “Medicaid,” but some states use more general phrases on the card, such as “medical benefits” or “medical assistance,” or have other names for the program, such as MediCal in California and TennCare in Tennessee.

Show this card every time you use a medical service. If you’re also enrolled in traditional Medicare, show your Medicare ID card, too (or your Medicare Advantage plan membership card if you’re enrolled in one of these plans).

Your Medicare Advantage plan membership card

This card bears your name, your membership ID number, the plan’s name and its Medicare identification number, and the plan’s customer service phone number. It must also say what type of Medicare Advantage (MA) plan it is: for example, health maintenance organization (HMO), preferred provider organization (PPO), or Private Fee-for-Service (PFFS) plan. The name of the insurance company that sponsors the plan may be incorporated in its name or shown separately. Of course, card designs vary among plans.

Use this card (not your Medicare ID card) to get medical services according to your plan’s terms and conditions. For example, if the plan restricts your choice of doctors to those within its provider network, its card won’t work if you present it at a doctor’s office outside that network — most likely leaving you responsible for the whole cost (except in cases of medical emergency). The exception is if you’re enrolled in a Medicare Cost HMO. In this situation, you can use your Medicare card for services outside the plan’s network regardless of medical urgency. Otherwise, you can’t use your regular Medicare ID card to obtain services when you’re enrolled in a Medicare Advantage plan.

If your plan includes drug coverage, you may be able to use the same card when filling your prescriptions or be given a separate card to use at the pharmacy, depending on how your plan does things.

Your stand-alone Part D prescription plan membership card

This card shows your name, your membership ID number, the plan’s name, its identification number, and its customer service phone number. The card likely has wording that indicates you’re entitled to Medicare prescription drug coverage. It may simply say PDP — initials that stand for prescription drug plan, the phrase Medicare uses for stand-alone plans.

Use this card to get your prescriptions filled under Part D if you receive your medical benefits from traditional Medicare or from a Medicare Advantage plan that doesn’t cover drugs (Medicare Cost plans, some PFFS plans, and Medicare Medical Savings Accounts).

Your card works like a key. It enables the pharmacist to access the Part D computer system and determine what you should pay for your prescriptions, according to the plan you have and what level of coverage you’re in — deductible, initial coverage, doughnut hole, or catastrophic coverage.

Your Medigap supplemental insurance card

This card shows your name and Medigap ID number, the name of the insurance company, its customer service phone number, and the type of Medigap policy you have, labeled with a letter of the alphabet — for example, MEDIGAP F.

Use this card to prove that you have separate insurance to help cover your co-pays for medical services when you’re enrolled in traditional Medicare. Show it every time you receive services from a doctor, hospital, or other provider.