If you joined an HMO because your doctor was in the network, only to find out she's left, you have no rights in many states for continued coverage for that doctor.

According to Families USA, only about one-fourth of states have enacted laws requiring health plans to continue paying for treatment provided by primary care doctors or specialists whose contracts with the health plan aren't renewed (for reasons other than quality-of-care problems, such as incompetence). Most of these state laws specify a minimum number of days that the health plan must provide transitional care.

You may be allowed to visit your old doctor

Minnesota became the first state to require HMOs to let patients continue to see doctors who are dropped from the network, and it was later followed by Florida, Kansas, Maryland, New Jersey, New York, Texas and Virginia, among others.

In Florida, if a contract between an HMO and a provider is terminated (for any reason other than for cause), they must allow HMO members for whom treatment is active to continue coverage through the completion of medically necessary treatment, until the patient picks another provider, or until the next open enrollment period offered by the HMO (not to exceed six months or through postpartum care if pregnant).

In 1998, California enacted a continuity-of-care law for high-risk patients (those with certain chronic or life-threatening illnesses) that allows them to continue seeing their doctor for up to 90 days if their doctor is dropped from their health plan.

Under the Patient Bill of Rights in Illinois, signed into law in August 1999, certain patients in managed care plans must be allowed transitional care. To qualify, patients must be in an ongoing course of treatment, which is rather murkily defined as "a condition or disease that requires repeated health care services pursuant to a plan of treatment by a physician because of the potential changes in the therapeutic regimen." Unfortunately, the laws do not always require the health plan to maintain payment at the same level. If you have to pay "out-of-network" costs, you may find yourself with a hefty medical bill.

If you think you're one of those patients, you are allowed to continue visiting your doctor for 90 days after the doctor leaves the plan. The doctor, of course, must agree to the plan's rules and fees first. (If you aren't sure if you're one of those patients, ask your health plan.)

In addition, women in Illinois in their third trimester of pregnancy must be given the option of continuing to see their doctor through postpartum care, just as in New York. Patients also must be given a 60-day notice that their primary care doctor is leaving the plan and all customers must be given information about their rights to transitional care.

Under Wisconsin law, if you were told at the time you joined a health plan that your doctor was in the plan's network, you must be allowed to see your doctor at no additional cost for the entire plan year if your doctor is then dropped from the plan. In addition, patients must be allowed to continue to see their specialist who is dropped for the course of their treatment or 90 days, whichever is less. And if you're in your second trimester of pregnancy, you can continue to see your doctor through postpartum care.

The exception to these Wisconsin laws is when your doctor is no longer practicing at all in your health plan's service area or if your doctor was terminated from the plan for "cause," such as malpractice, fraud or other wrongdoing.

Interestingly, Wisconsin law requires your HMO to give you a 30-day notice if it terminates its contract with your primary care doctor, but it does not have to notify you at all if it terminates its contract with your specialist. (There's a lesson here: Before you visit your specialist, double-check that he or she is still in your network.)

If you're facing the problem of having your doctor dropped from your network, contact your state department of insurance to find out what your rights are for continued coverage for that provider.