The U.S. could face a shortage of as many as 90,000 physicians because of a growing elderly population, according to a report published last week by the Association of American Medical Colleges (AAMC). The report also predicts that the greatest physician shortfall will be in the demand for surgeons who treat diseases in the elderly.

The report says the growth in the insured population due to the Affordable Care Act will have little impact on the need for more physicians  – just two percent of the projected growth in demand, AAMC said. Instead, an “increasingly older, sicker population, as well as people living longer with chronic diseases, such as cancer, is the reason for the increased demand.” The population of those over age 65 is estimated to grow 46 percent by 2025.

Overall, the number of specialists will fall short of demand by between 28,200 and 63,700 physicians by 2025. In addition, the report authors expect that the demand for primary care practitioners will exceed supply by about 12,500 to 31,100 physicians.

Last year, three separate bills were circulated in Congress to increase federal residency slots to 3,000, at an estimated cost of $1 billion per year, but none of them went forward. Currently, the government provides a $40,000 share of the cost of training each U.S. physician – estimated at about $152,000 annually – via the Medicare program.

The group is calling on Congress to pass a bill to increase residency slots. According to AAMC, "hospitals have really hit the point where their margins are razor thin, and they have no wherewithal to invest in residency training." In addition, the average medical student graduates with an average debt of $180,000 per year, with students hard-pressed to make up these costs themselves.

In 2013, there were about 767,000 physicians practicing in the United States, according to the report.

The AAMC represents all 141 U.S. medical schools and 17 in Canada, as well as 400 major teaching hospitals and health systems, including 51 Department of Veterans Affairs medical centers.

To read the AAMC report, click here.