How much is freedom worth to you?

If it's worth an extra 10 or 15 bucks, you might be interested in an HMO that Aetna U.S. Healthcare offers.

The group health plan, called Aetna Open Access, gives you the freedom to visit any specialist in its HMO network without first getting a referral from your primary care doctor.

Aetna officials say employers and their employees want fewer restrictions in their HMOs. The Connecticut Department of Insurance (DOI) agrees, noting that patients want the flexibility to bypass their primary care doctor known as the "gatekeeper" in a traditional HMO and go directly to the specialist of their choice.

"Theoretically, when HMOs were first developed, the feeling was that a gatekeeper plan, where you went to your primary care physician and had to get a referral to a specialist, offered better control over someone's health," explains Mary Ellen Breault, Director of the Life and Health Division of the Connecticut DOI.

Today, Breault says, most health insurers offer a choice of group plans allowing employers to choose the level of freedom. "Employers usually want a choice," she says.

But choice comes with a price. In Aetna's case, most patients enrolled in the Open Access plan will pay a $20 to $25 co-payment each time they visit a specialist without a referral, rather than the typical $10 co-pay. Even visits to the ob-gyn would cost more, although many states have laws allowing women access to their ob-gyn without a referral anyway. Aetna also offers a version of Open Access with lower co-payments, but higher premiums. Another variety of Open Access allows patients to visit out-of-network doctors — again, for a higher out-of-pocket cost.

"One size doesn't really fit all," says Elizabeth Sell, a company spokesperson.