Mayo Clinic will start taking referrals for specialty care from a company that runs on-site clinics for employers, the latest example of a Minnesota-based health system sizing up the market for patients who get health care in the workplace.

With the new agreement, Rochester-based Mayo Clinic will offer services to patients with costly and risky conditions who initially were seen at clinics run by Tennessee-based Premise Health. Employers hire Premise Health to operate on-site wellness centers — destinations in the workplace that offer a combination of primary care, pharmacy, occupational health and wellness services.

Premise Health is a private company that doesn't release financial data. No money is flowing between the company and Mayo, though, said Lacey Hunter, a spokeswoman for Premise Health.

"When a member engages with Premise, that engagement falls under the contract with the client," Hunter said in an e-mail response to questions. "When a member engages with Mayo, that engagement likely falls under the client health plan and is paid out as one would normally if they were visiting any specialist or hospital."

A spokeswoman for the clinic said the arrangement could help Mayo connect with more large employers that sponsor health plans and are seeking treatment options for enrollees with complex-care needs.

In a news release, Dr. David Hayes of the Mayo Clinic said, "We look forward to working closely together to deliver seamless experiences, improve outcomes and enhance care."

Bloomington-based HealthPartners opened its first Well@Work center in 2006, and last year was operating 16 on-site clinics for more than 65,000 employees in Minnesota. Last year, Minneapolis-based Fairview Health Services launched a portfolio of workplace health and wellness services including on-site clinics.

Premise Health said about 90% of its 600 wellness centers are located at work sites, with the remainder located in communities close to where employees live. Premise Health operates centers in 44 states, with more than 15 locations in Minnesota, Hunter said.

Mayo and Premise Health describe their relationship as a "centers of excellence" agreement.

Those programs typically steer patients from across the country to a select group of hospitals for certain medical services. Mayo said it currently has a centers of excellence program with retail giant Walmart and has other relationships in development.

Historically, health insurers have been directly involved in promoting the centers of excellence idea, with Minnetonka-based UnitedHealthcare first launching a program in the 1980s. In 2015, Minnetonka-based Medica announced it would provide travel benefits to new subscribers in Iowa and Nebraska for treatment of a few complex conditions at the Mayo Clinic in Rochester.