Do I Need Medicare Supplement Insurance If I Am Only Enrolled in Part A?

Original Medicare has two parts--Hospital Insurance Part A, and Medical Insurance Part B. Both parts have deductibles, coinsurances, and co-pays. Supplemental Medicare Insurance--Medigap--can cover these costs. However, beneficiaries enrolled in just Part A of Medicare cannot purchase Medigap policies.

Part B Facts

• Medicare Part B covers physicians' charges inside and outside the hospital, lab tests, therapy, and preventative medical services such as mammograms and flu shots. Medicare recipients enrolled in Part A have to pay all these costs only if they have no other insurance such as group insurance.

Medigap Coverage Needs

• Medicare Part A does not pay all hospital costs--for example, the deductible for one hospital stay is $1,100 for 2010. A recipient enrolled in Part B of Medicare must pay an annual deductible of $155, after which Medicare pays 80 percent of approved services--the patient pays the other 20 percent. Unless the recipient purchases a Medigap policy, he or she will be responsible for these medical costs.

Group Health Insurance

• Individuals with group health insurance normally do not need Part B of Medicare, since it would duplicate coverage. If the group insurance terminates for any reason, the individual may qualify for a special enrollment period for Part B, during which he or she can enroll without a waiting period or late-enrollment penalty at a Social Security office. Upon enrolling, the individual may then purchase a Medigap policy.

VA and Military

• Medicare recipients who have medical coverage from the U.S. Department of Veterans Affairs or TRICARE coverage for active military members may not need Part B. Medigap policies will not supplement these types of medical insurance.