POCATELLO, Idaho - South Dakota has a medical school to serve its 746,000 people. With about 600,000 residents each, both North Dakota and Vermont train doctors within their borders.

The numbers cause medical educators at Idaho State University, which offers most of the state's health services training, to blanch. Despite sprinting growth and 1.4 million residents - more than both Dakotas combined - Idaho has no medical school.

The university, so far, has not even been able to persuade lawmakers to pay for a feasibility study on an in-state medical school. Educators grouse that the state should do more in response to ranking 49th or 50th in the nation in the ratio of doctors or residents.

Arthur Vailas, the school's new president, concedes that starting a medical school is not as simple as buying stethoscopes and adding a few classrooms. First, the school needs to groom research faculty, expand residency programs and bolster partnerships with state hospitals, he said.

Idaho, a state with a famously thrifty Legislature, would also have to provide millions of dollars in startup costs.

Still, Vailas - a former National Institute of Health fellow and NASA researcher who was chosen largely on the back of his medical credentials - says Idaho's doctor shortage could worsen if the state continues to drag its feet.

"Everybody is guessing, it's going to cost $400 million, $200 million, $20 million, $15 million," he said on campus in the potato-farming town of Pocatello. "The point is to just do a study and find out."

Idaho is one of only a handful of states without its own medical school. Others include Wyoming, Alaska, and Montana, and for many years all four states have belonged to a cooperative program that reserves spots for their students at the University of Washington School of Medicine in Seattle.

Each year, 18 Idaho students are admitted to the school. Another eight annually attend the University of Utah School of Medicine in Salt Lake City, though a separate partnership.

Idaho subsidizes their tuition to offset the higher out-of-state fees. But, a homegrown medical school could provide more return on Idaho's investment - providing a pipeline of doctors into the state.

For one, many Gem State students who receive their training in Seattle or Salt Lake City never return. What's more, competition for the seats is fierce.

Last year, 161 Idaho students applied to medical school, many to the five-state University of Washington compact, compared to fewer than 130 in 2004 and about 60 when Idaho first bought 18 seats in the program in 1972, said Ronald McCune, Idaho State's vice president of medical education.

"We have the issue of access to doctors, but we also have 160 students vying for 26 seats," he said. "This state really needs to address these shortages at both ends of the spectrum."

Though the Legislature will consider requests to pay for more seats in Washington and Utah for Idaho's would-be doctors, Idaho State wants to base a new program on campus. Officials there say the state could build it without a bricks-and-mortar approach.

The university already has the teachers and classroom infrastructure for the first year of medical school that could overlap with programs in advanced biology, dentistry, pharmacology and others, said Linda Hatzenbueler, dean of Idaho State's Kasiska College of Health Professionals.

The school would need money to forge partnerships with hospitals and hire enough teachers for the second year of medical school, Hatzenbueler said.

An in-state medical school also could offer clinical experience to third and fourth year students away from far-flung Pocatello, with hospital rotations in population hubs like Boise, Coeur d'Alene and Idaho Falls.

"We don't want a new building," Hatzenbueler said. "We're talking about making this a statewide program that utilizes the whole state. I mean Boise is where the pathology is, it's where the sick people are."

But Vailas admitted that the hype of a medical school diverts attention from another root of the doctor shortage: the lack of residency programs.

Residency programs place doctors in a supervised practice after they graduate from medical school.

Bob Seehusen, CEO of the Idaho Medical Association, an advocacy group for most physicians in the state, said Idaho has only 15 places for residents each year - six in an Idaho State Program and nine slots at hospitals in the Boise area filled through the University of Washington's Family Medicine Residency Network.

Both residencies are for family physicians, meaning Idaho students who want to practice specialized medicine must spend years out of state, whittling the likelihood of their return.

While the association supports a feasibility study, and also is pushing a plan to expand Idaho's spaces in the Utah and Washington schools by at least four seats, the first step to improving health care in Idaho would be to boost residency programs, Seehusen said.

Dr. Jonathan Cree, director of Idaho State's family practice residency program that has placed doctors in rural eastern Idaho towns like Rexburg and Burley, said recruiting doctors to rural areas is particularly difficult in Idaho.

Many students prefer the higher pay and lighter hours of doctors in Seattle, Salt Lake or any urban center where they may study medicine.

"It's a difficult life," Cree said. "You need a physicians where income level is not a major priority, who have a major dedication to the underserved."