CHICAGO -- A doctors group expects a serious shortfall of family doctors in at least five states by 2020.

Population growth and rising numbers of elderly in Nevada, Arizona, Florida, Texas and Idaho will make the need in those states most critical, said Dr. Perry Pugno of the American Academy of Family Physicians.

"As Americans age, they need more health care interventions and primary care is the most cost effective way to help them maintain their health," Pugno said.

The number of U.S. medical graduates going into family medicine has been falling -- by more than 50 percent from 1997 to 2005 -- with many young doctors preferring specialties that pay more and offer more control over work hours.

The group's report estimates the number of family doctors must grow by 39 percent during the next 14 years to keep up with the nation's needs. All states will need more family doctors by 2020, the report states, with Nevada topping the list.

Dr. Rudy Manthei, a Las Vegas opthamologist and chairman of Keeping Our Doctors in Nevada, said he's not surprised by the report. One obvious reason Nevada needs more family physicians is the state's population surge.

Other reasons include lack of family medicine residents, low reimbursement rates from Medicare and private health insurance plans, and older physicians leaving because they are unhappy or retiring.

"We have a lack of resources when it comes to primary care,'' he said. "Touro University (Nevada), which is a school of osteopathy medicine, is graduating their third-year class this year and traditionally they go into primary care. Hopefully, that will help -- if they stay -- but we still have to deal with those other issues.''

Earlier this month, the American Medical Association announced that the U.S. government plans to cut Medicare doctor payments by 5.1 percent, almost $200 billion, between 2007 and 2015.

For Nevada physicians that could mean lowering reimbursement payments by an average of $234,000 in the next nine years -- $26,000 per year. Primary care physicians are said to be the most hurt by these declines because they see the most patients.

Dr. Lisa Haworth, a family physician in Henderson, said some medical students who were planning to go into family practice are switching to specialities that have more to do with treating lifestyle issues, such as cosmetic surgery.

A decline in primary care physicians has been a problem for several years, she said.

"The number of residents has declined and, as a result, we are going to have fewer doctors in this area in the future because obviously the residents are the ones who are going to be the future doctors,'' she said.

Earlier this year, Haworth dropped about 1,000 of her patients carrying Anthem Blue Cross because the insurance company decided to lower payments to physicians. Currently, Haworth has about 3,000 patients.

The doctors group wants Congress to increase Medicare payments to family doctors to help ease the shortage, Pugno said. The group also urges voters to question candidates about health care, an issue as important to voters polled by the group as the war in Iraq and terrorism, Pugno said.

Review-Journal staff writer Annette Wells contributed to this report.