If you owe a pile of money on medical bills and can't figure out how your health insurance is supposed to work, it might be time to hire a professional to help you sort it out.

Amid the growing complexity of the health care system, an increasing number of consultants are specializing in helping people with their medical insurance claims and health care bills. Claims assistance professionals help track, organize and file health insurance claims, negotiate medical bills with providers and appeal denied health insurance claims.

The field is still relatively small. The Alliance of Claims Assistance Professionals has about 50 members. Most members spent years in medical careers where they gained billing and health insurance claims experience and then went into business for themselves to help consumers.

Medical billing advocates, similar to claims assistance professionals, also help people with health insurance claims, although many focus on disputing incorrect hospital bills. Medical Billing Advocates of America, a trade group founded in Roanoke, Va., in 1997, sells courses to people who want to become advocates and a handbook for consumers.

For simple, routine health insurance claims, you don't need a professional's help. But if you have a serious health condition, owe a lot of money on medical bills and don't understand why your health insurance plans aren't paying the way you expected, you might want to consider getting help. Expect to pay at least $60 an hour for a claims assistance professional; fees can go up to $150 an hour. Some medical billing advocates charge a percentage of how much they save you on medical bills, typically 35 percent.

Look for a professional who has experience working in the field of medical billing from an insurance, hospital, physician's office or clinic's perspective, and offers the kinds of services you need. Ask how the consultant has helped other consumers in situations similar to yours. Get references and check them.

Many professional advocates are willing to offer a free initial consultation to learn about your needs and let you know whether they can help.

But don't expect miracles. If your health insurance policy clearly states that it doesn't cover maternity care, no one can talk the health insurer into paying for your prenatal visits.