COLUMBUS, Ohio - Getting face time with the family doctor could soon become even harder.

A shortage of primary care physicians in some parts of the country is expected to worsen as millions of newly insured Americans gain coverage under the federal health care law next year. Doctors could face a backlog, and patients could find it difficult to get quick appointments.

Attempts to address the provider gap have taken on increased urgency ahead of the law's full implementation Jan. 1, but many of the potential solutions face a backlash from influential groups or will take years to bear fruit.

Lobbying groups representing doctors have questioned the safety of some of the proposed changes, argued they would encourage less collaboration among health professionals and suggested they could create a two-tiered health system offering unequal treatment.

Bills seeking to expand the scope of practice of dentists, dental therapists, optometrists, psychologists, nurse practitioners and others have been killed or watered down in numerous states. Other states have proposed expanding student loan reimbursements, but money for doing so is tight.

As fixes remain elusive, the shortfall of primary care physicians is expected to grow.

Nearly one in five Americans already lives in a region designated as having a shortage of primary care physicians, and the number of doctors entering the field isn't expected to keep pace with demand. About a quarter-million primary care doctors work in America now, and the Association of American Medical Colleges projects the shortage will reach almost 30,000 in two years and will grow to about 66,000 in little more than a decade. In some cases, nurses and physician assistants help fill in the gap.

The national shortfall can be attributed to a number of factors: The population has aged and become more chronically ill, while doctors and clinicians have migrated to specialty fields such as dermatology or cardiology for higher pay and better hours.

The shortage is especially acute in impoverished inner cities and rural areas, where it already takes many months, years in some cases, to hire doctors, health professionals say.

The problem will become more acute nationally when about 30 million uninsured people eventually gain coverage under the Affordable Care Act, which takes full effect next year.

"There's going to be lines for the newly insured, because many physicians and nurses who trained in primary care would rather practice in specialty roles," says Dr. David Goodman of the Dartmouth Institute for Health Policy and Clinical Practice.

State legislatures working to address the shortfall are finding that fixes are not easy.

Bills to expand the roles of nurse practitioners, optometrists and pharmacists have been met with pushback in California. Under the proposals, optometrists could check for high blood pressure and cholesterol while pharmacists could order diabetes testing. But critics, including physician associations, have said such changes would lead to inequalities in the health care system -- one for people who have access to doctors and another for people who don't.

Other states are experimenting with ways to fill the gap.

Texas has approved two public medical schools in the past three years to increase the supply of family doctors and other needed physicians. New York is devoting millions of dollars to programs aimed at putting more doctors in underserved areas. Florida allowed optometrists to prescribe oral medications -- including pills -- to treat eye diseases.

The federal health care law attempts to address the anticipated shortage by including incentives to bolster the primary care workforce and boost training opportunities for physicians' assistants and nurse practitioners. It offers financial assistance to support doctors in underserved areas and increases the level of Medicaid reimbursements for those practicing primary care.

Providers are recruiting young doctors as they gear up for the expansion.

Even so, many experts say the gap between doctors and those gaining care under the health reforms in many parts of the country will not close quickly. Access to care could get worse for some people before it gets better, said Dr. Andrew Morris-Singer, president and co-founder of Primary Care Progress, a nonprofit in Cambridge, Mass.

"If you don't have a primary care provider," he said, "you should find one soon."