The number of active doctors continues to rise while more students are enrolling in medical school, according to new data from the Association of American Medical Colleges.

In its new 2013 state physician workforce data book, the AAMC says the ratio of active physicians per 100,000 people in the United States rose to 260.5 from 254.5 between 2008 and 2012. Meanwhile, the number of students enrolled in medical schools jumped to 102,498 in 2012 compared to 91,474.

The report comes despite some polls and political pundits that have physicians second-guessing their medical careers due to rapid change in the U.S. health care system in part brought on by the Affordable Care Act.

“Medicine continues to be a very attractive career choice among the nation’s best and brightest, with record numbers of students applying to medical school for the first time and enrolling in classes this fall,” said Dr. Darrell Kirch, president and chief executive officer of the AAMC, which represents the nation’s more than 140 medical schools and some 400 teaching hospitals. “The nation is changing rapidly, demographically, and healthcare as a system and physicians as a group of professionals are responding.”

Still, there could be doctor shortages as the health law brings millions of Americans coverage next year and patients seek primary care doctors and other physicians that are in less supply in certain parts of the country. The number of active physicians per 100,000 people ranges from a high of 421.5 in Massachusetts to a low of 180.8 in Mississippi, the AAMC report said.

In addition, the number of active physicians is getting older with 27.6 percent of active physicians 60 years of age or older while just 17 percent of active physicians were under 40.

Already, the AAMC has projected a shortage of more than 90,000 physicians by 2020.

While more medical schools are opening and students are flocking to these graduate programs, there may not be enough residency slots to train these students once they graduate.

The Balanced Budget Act of 1997 capped the number of available slots for residents coming out of medical school as part of the law’s reduction in spending on Medicare, which largely funds residency programs. Meanwhile, Congressional gridlock is keeping the funding of doctor training programs off of any front burners in Washington.

“Medical schools are doing their part,” Kirch said. “The students are doing their part but no MD graduate can care for their community until they go through a residency.”

“Now it’s time for Congress to do its part by lifting the 16-year-old cap on the number of residency positions for which the federal government pays its share of the training costs.” Kirch said. “If lawmakers don’t act now, we face the very real risk of not having enough doctors for our growing and aging population.”