Health insurer Humana (NYSE:HUM) and CVS Caremark's (NYSE:CVS) MinuteClinic are expanding their relationship, in what looks like a healthy deal for both sides.

MinuteClinic has been part of Humana's network of providers since 2006, but now the companies are collaborating to send more of Humana's members to MinuteClinics.

Humana and other health insurers like UnitedHealth Group (NYSE:UNH) and Cigna (NYSE:CI) need to keep the payments their members incur down to a minimum. A nurse practitioner at a MinuteClinic should cost less than a doctor performing the same service. MinuteClinics are open on weekends, which should help Humana avoid high-priced charges from emergency rooms for non-emergencies that can't wait until the doctor reopens on Monday. Of course, Humana has to make it sure it's not so accessible that members go to the clinic for little things like a hangnail or other stuff that will clear up on its own, but that can be somewhat discouraged via a co-pay.

The partnership also involves MinuteClinic encouraging members to go to Humana's health coaching services, LifeSynch. Getting members healthy can be one of the best ways to help keep health-care costs down.

As part of the partnership, Humana is setting up a health clinic staffed by MinuteClinic in one of its offices for its employees and dependents. Some companies -- Google (NASDAQ:GOOG) for instance -- already see the benefits of on-site clinics, but that number may increase as companies realize the perk has a payback by keeping employees healthy and at work. Like catering in the cafeteria, adding an on-site health-care provider is something that a lot of companies will choose to outsource. CVS Caremark seems to be setting itself up as the go-to provider.

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Fool contributor Brian Orelli, Ph.D., doesn't own shares of any company mentioned in this article. The Fool owns shares of UnitedHealth Group and has a very healthy disclosure policy.