Some experts, however, believe that the real problem is not an overall shortage of doctors but an imbalance in the use of existing resources. For example, there may be too many specialists and too few primary care doctors; too many professionals in cities and affluent areas, too few in rural or impoverished areas; too many doctors doing routine procedures that could be handled by advanced-practice nurses, physician assistants or pharmacists.

In any case, there is a desperate need for accurate, up-to-date information. But congressional Republicans, who refuse to cooperate in any way with the Affordable Care Act, have blocked a commission that was supposed to sort it all out and make recommendations. The reform law created a National Health Care Workforce Commission, whose members were appointed in late 2010, but the panel has never met and it has no staff or budget to support its operations. This year, President Obama gave up even requesting $3 million for the panel, after losing that battle in previous years.

One obstacle to producing enough doctors is a shortage of residency slots in teaching hospitals to provide clinical training for doctors who have just graduated from medical school. Medical school enrollments and the number of medical schools have soared over the past decade, statistics show, but the number of residencies to train graduates has increased only modestly, largely because of a congressional cap on paying for the slots.

Another hurdle that will potentially affect nurses and physician assistants — as well as students in medical and osteopathic schools — in coming years is an expected shortage in clinical training sites in community hospitals and clinics. This is where students get the hands-on experience they need to supplement classroom instruction and earn their degrees.

There are bills in Congress to increase the number of residency slots for new doctors by 15,000 over a five-year period. This seems entirely warranted, given the increase in doctors who will be pouring out of the medical schools. Whether Congress will appropriate the money needed for that purpose — on top of spending large sums to rehabilitate the Department of Veterans Affairs health system — is questionable.