For the last time in 31 years of practicing medicine in Dallas, Dr. Bill Walton slips into the examining room at his family practice office near Medical City Dallas Hospital to see a patient.

He sits next to 63-year-old Maggie Moore, one of the first patients who came to see him when he opened his practice in Dallas. He listens to her litany of aches and pains, reviews her lab tests and finishes up by urging her to exercise more and eat less.

It's the kind of routine care that Walton has carried out since 1978 as a solo practitioner in Dallas. But he has decided to quit the practice that he carefully built – and not so he can retire and pursue his beloved pastime of bird-watching.

Fed up with the business side of medicine, he has accepted a salaried position with Scott & White Healthcare in Temple.

"This opportunity will free me to practice good medicine without the pressures of the 'business' of medicine," he explained in a letter to his patients announcing his decision this summer.

Soft-spoken, unhurried, yet firm, the 60-year-old physician is a throwback to the kindly doctor seen on the old TV show Marcus Welby, MD. Beloved by his patients and employees and respected by his peers, he was appointed president and, this year, chairman of the Dallas County Medical Society.

He is leaving Dallas because of the pressures and costs of running his solo practice, including longer hours and lower pay. His experience shows why fewer medical students are entering primary care, and why family doctors are becoming an endangered species.

•An avalanche of paperwork, ever-changing insurance plans and complex rules for collecting payments have created acutely complicated administrative hassles and higher office expenses.

Walton grew weary of fighting through obstacle courses erected by insurance carriers and government agencies to control payments to doctors – barriers that resulted in a loss of time with patients and income. "I have had to deal in my practice with 300 to 400 different insurance plans – each with different rules, co-pays, deductibles and coverage variations," Walton says.

•A payment system that ultimately rewards doctors, not for the quality of their medical care, but for the number of procedures they do – the more, the better. "I get nothing for phone calls, e-mails, coordination of care with the hospital and specialist, filling out forms, interpreting and acting on test results or filling fax or phone prescriptions," Walton says.

•Pressure to see more patients per day. Reimbursements from insurers and government programs failed to keep up with the rising expenses of running a medical practice. Doctors wage annual fights with Congress over Medicare's physician-fee schedule, which consistently undervalues primary care physician services in relation to specialists, according to the American Academy of Family Physicians.

Seventy percent of medical office managers reported that operating costs are increasing faster than revenue, according to a survey released this month by the Medical Group Management Association.

Quality of care suffers, Walton says, because shrinking revenue puts pressure on primary care doctors to do more in less time. "It was a case of having to go faster and faster to pay for the expense of owning a medical practice in the face of reimbursements that didn't keep up with inflation," he says.

Walton says he cannot wait any longer for reform.

"I hear over and over again from medical organizations and politicians that we need to change the payment structure to encourage more primary care," he says. "All we get is lip service. Insurance companies have continued to squeeze every dollar out of the system that they can, and Medicare continues to give only paltry raises."

Walton arrived in Dallas in 1978, from a small fishing village in Canada, where he started his career. (His mother is from the United States and his father is from Canada, and the family lived in both countries when Walton was growing up.)

Walton favored the universal health care that Canada offered but thought the government-run system was too bureaucratic. He was also discouraged by his pay – which came to a lowly $8 an hour – in today's dollars about $21 per hour, or a little more than $40,000 a year.

In Dallas, Walton quickly established himself. A solo practitioner from the start, his practice thrived; he had 3,500 active patients when he left in August. His patients liked his personal, folksy approach, which included the mellowing presence of his faithful Duffy, a King Charles spaniel.

When Walton started out, most of his patients paid their own bills and requested repayment from their insurers. By the mid-1980s, insurance companies tried controlling skyrocketing health care costs with "managed care" policies. These plans set doctors' fee schedules and screened out services considered unnecessary.

These controls also led to more administrative expenses – costs that fell hard on solo family physicians like Walton.

In 1980, the average physician in Texas had only two nonmedical employees, says Donna Kinney, director of data analysis for the Texas Medical Association. By 2000, the number of nonmedical employees per physician had more than doubled to five, Kinney says. Walton says he had nine to 12 employees in recent years; most dealt with administrative tasks.

Those nonclinical employees were needed to navigate the complex maze of insurance requirements, including pre-authorization of services and specialist referrals. They had to process, file and then bird-dog insurance claims, which were denied or delayed if not filled out with the precise coding and policy numbers.

"Almost everybody has a different deductible, a different co-pay. Some of the plans pay for preventive services 100 percent. Some of them don't pay for preventive services at all," Walton says. "So many permutations and computations, so with every patient that comes in, you have to research what kind of coverage they have, so you know how to charge them."

Recently one of Walton's patients, who'd had breast cancer 10 years ago, asked for a simple blood test to screen for cancer. She had to agree in advance to sign a waiver that she would pay for the test, Walton says. His office had to research whether her insurance policy would pay for the screening and whether it should be billed under preventive or diagnostic services – a time-consuming activity that might take weeks of phone calls and e-mails with the insurer.

While Medicare's eligibility rules do not change as much as private insurance policies', the government program consistently underpays for medical services, Walton says. In 2008, only last-minute action by Congress averted a 10 percent pay cut in physician payments by Medicare – a cut that would have forced 40 percent of doctors to reduce or eliminate their Medicare patients, according to the academy of family physicians.

Doctors feel they have lost control of their livelihood, Walton says. "We lost the ability to have free enterprise. ... Our fees are set by somebody else – unless we do cash only."

Managed care insurance plans "gave us so little money we couldn't manage the patients' care," he says. "Frankly, they were run by insurance companies. And their goal wasn't to keep patients healthy, it was to make money."

Managed care changed the traditional doctor-patient relationship into more of a business transaction. Doctors felt pressured to see additional patients per day, running them through the office like an assembly line.

For Walton, the idea of squeezing more and more patients into his day was out of the question. "I just can't see 40 patients a day," he says. With his patient mix, he could only see an average of two dozen patients a day.

"I happen to have a lot of very complex patients, elderly patients, and people with multiple health problems, diabetes, arthritis, heart disease and hypertension. Instead of having one problem, those patients have five or six problems," he says. "And you can't spend five minutes with them. You have to spend 25 minutes with them."

His own income has been on a slow decline over the last 10 to 15 years, falling below national averages. A nationwide survey of doctors showed that incomes for primary care physicians ranged from $165,000 to $211,000 with an average at $181,000.

"I'm well below that," says Walton, who did not want to reveal his exact income. But he would reveal that his income fell below $165,000, the low end of the range for primary care physicians cited by the survey.

"I made over $200,000 15 years ago," he says. Factoring inflation, that income was about twice as much as he makes now.

Walton says he sold his practice for less than $100,000, not much return on investment after 31 years.

The same reasons he gives for leaving (longer days, lower pay and the increasing administrative operating costs) have been cited as major causes of a sharp decline in the number of medical students choosing to practice primary care medicine – a drop of nearly 52 percent since 1997, according to the academy of family physicians.

A shortage of such doctors looms just as baby boomers are entering a time of life when they'll require more medical care. A recent federal government report projected that by 2020, the nationwide supply of primary care physicians will be 66,000 fewer than needed.

That trend won't improve until the health care system undergoes fundamental changes, Walton says.

"The biggest problem with health care is the way it's structured," he says. "We don't have a structure that rewards people for saving money. Doctors are not rewarded for taking care of people; they are rewarded for fixing a problem, and spending more money is a good thing in our system – except ultimately it drives costs up."

Walton's new employer, Scott & White Healthcare, uses a different approach, called "accountable care." The 800 physicians who work at Scott & White's nine hospitals and 50 clinics work in collaborative teams. They receive frequent feedback on the cost and quality of care they give patients. Bonuses are given for both quality and efficiency.

Walton says he will make about the same income as he did in his solo practice without any of the administrative burdens.

He loved living in Dallas and raising his two sons there with his wife Barbara, a tax director at PricewaterhouseCoopers. "Both of our sons and our grandchildren are sad that we've left the Dallas area. We used to see the grandchildren a few times a week," Barbara Walton says.

She wonders if her husband's leaving also marks the passing of an era. "It's almost as if the days of the solo practitioner are gone," she says. "There's an overwhelming amount of administration, and it's especially hard on a solo practitioner."

Judging from the tears and comments he got on his last day, his patients are going to miss him, too. Several have vowed to remain in his care, even if it means making the three-hour drive to Temple.

"He's a heckuva fine fella," says Joe Willoughby, a Dallas resident who's been a patient of Walton's for 10 years. "Good doctor. Good citizen. Good leader. I'm really disappointed he's leaving."

At the end of his examination, Willoughby hugged his doctor.

"Good luck, pardner," he says. "I might have to go down to Temple to see you."

Staff writer Bob Moos contributed to this report.