Health plans like hospitals that provide care efficiently.

So, if patients with certain health problems are far from these medical centers, more insurance policies are offering to cover the travel costs.

"When you do a good job of taking care of people … you typically also end up paying less for their care," said Dr. Richard Migliori, chief medical officer for Minnetonka-based UnitedHealth Group, the nation's largest health insurer. "There's a quality dividend."

Travel benefits are part of "centers of excellence" programs. They've been around for decades, but interest seems to be growing again as employers and insurers try to contain health care costs.

Some hospitals and doctors are wary of the trend, though.

Medical centers should be recognized as superior when they truly deliver higher-value care, said Dr. Donald Jacobs, president of the Minnesota Medical Association. But there are suspicions that insurance company programs are driven primarily by cost, not quality.

"You run the risk of driving patients away from really good providers … based on what I'll call the marketing concept of excellence, as opposed to the measurable difference," Jacobs said.

There aren't numbers that track exactly how many patients are crossing state lines as part of centers of excellence programs.

But in May, Minnetonka-based Medica announced it would provide travel benefits for new subscribers in Iowa and Nebraska, if patients want to travel for treatment of a few complex conditions at the Mayo Clinic in Rochester.

In 2013, a San Francisco-based organization called the Pacific Business Group on Health launched a program for several large national employers, including Wal-Mart, to send joint replacement patients to a select group of medical centers. This year, the group started a similar program for spine surgery.

UnitedHealth's insurance division is expanding a new centers of excellence program that covers travel for patients seeking knee or hip replacements at certain hospitals.

Such programs make sense given changes with the Affordable Care Act, said Dr. Charles Rosen, medical director for Mayo's department of contracting and payer relations.

More patients have "narrow network" insurance policies where financial incentives steer patients to a limited set of doctors and hospitals. Those health plans can be augmented, Rosen said, by including access to centers of excellence for certain conditions.

"There's a need to look for the specialty care, the highly complex care procedures, to be done elsewhere," he said. Even so, such programs generate a "very small" share of all Mayo patients, Rosen said.

UnitedHealthcare first launched a centers of excellence program in the 1980s. The company started with solid organ transplants and has since added bariatric surgery, cancer, infertility, neonatology and other conditions.

For health plans that include travel benefits, per diem caps for lodging and meals range from $150 to $200. Transportation benefits apply when people travel 50 or more miles. Overall reimbursement is commonly capped at $10,000.

"If it's an adult patient, another adult can travel with and we'll cover the cost of lodging and so forth, for both the patient as well as for their accompanied adult," said Migliori, the company official. "For children, we'll send two adults."

The insurer offsets travel costs by negotiating a lower unit price for services at the centers, he said, although the bigger source of savings is reduced complications.

A few years ago, UnitedHealthcare launched a pilot program in which a large national employer directed joint replacement patients to one top-rated medical center.

"The differences in outcomes were so significant, that it was worthwhile moving people across the country to do it," Migliori said. "Employers now are lining up to have this, and we're expanding it now to five markets."

At the Pacific Business Group on Health, a key aspect with the travel program is making sure doctors back home will provide follow-up care, said Olivia Ross, the group's associate director. Out of more than 600 patients who have traveled thus far, about 60 percent have flown, Ross said. The others drove.

In Minnesota, large employers have offered centers of excellence programs for years, said Carolyn Pare, chief executive for the Minnesota Health Action Group. What's new, Pare said, is that some employers now offer to cover not just travel costs, but also copays and deductibles that are more common features in benefit plans.

"We are seeing more self-insured employers put in benefit differentials and travel benefits that create that incentive for their beneficiary to make the choice of a center of excellence," said Garrett Black, senior vice president of health collaboration at Eagan-based Blue Cross and Blue Shield of Minnesota.

In 2010, the Blue Cross program dropped the University of Minnesota Medical Center as a destination for certain bone marrow transplants, instead pushing them to travel to Mayo Clinic.

Losing the designation cost the hospital money, and U officials spent a lot of time explaining why they felt the insurer's criteria wrongly penalized the bone marrow program, said Dr. Daniel Weisdorf, director of the U's adult blood and marrow transplant program. One year later, the U was reinstated as a high-quality center, and Weisdorf said he became more of a believer in the programs.

"There is a cynical view in the minds of many that insurers' definition of value is only price, and not outcomes," he said. "But I actually think they're interested in both."

Not everyone is convinced.

Jacobs of the Minnesota Medical Association said that when he's looked at some programs, it's hard to find true differences in patient outcomes between the centers included vs. the others. In such cases, the center of excellence label seems to simply restrict choices, he said.

The Minnesota Hospital Association worries that medical centers don't always have full information about what goes into an insurance company's rating system, said spokeswoman Wendy Burt. Besides, there's something to be said for patients getting care close to home, without going through the hassle of travel, she said.

"It needs to be measures based on quality of care, and lowest cost," Burt said. "It can't just be based on what's the cheapest."