But Humana’s retail reach extends far beyond the Guidance Centers that it has opened in Florida and other states in recent years. For example, starting on Monday, more than a million people enrolled in the insurer’s HumanaVitality wellness program will be eligible for 5 percent savings at Walmart stores on purchases of fresh fruits, vegetables and other grocery products that meet the nutritional standard for the retailer’s "Great For You" label.

Going mobile

The insurer has gone mobile, too. Owners of all Apple and Android smart phones and tablets can download the insurer’s mobile application free of charge. Users of the MyHumana Mobile App can identify doctors they need to visit, fax their identification cards to verify benefits, and find the lowest-cost medication. Downloads of the award-winning mobile app have tripled in the last 12 months.

"The health-plan landscape is changing, and we need to adapt," Javier Mendoza, vice president of strategic marketing at Miami-based AvMed Health Plans, said in an email exchange. "The expected growth in the individual market ... will lead to a shift in more direct-to-consumer marketing, so messaging will change to reach individuals, not just business decision-makers who are choosing what plans to offer their employees."

Like most insurance underwriters, Aetna has more experience marketing employer-sponsored group health plans than individual medical coverage. The 159-year-old insurance company introduced individual medical policies in Florida about six years ago to serve people who have jobs but no coverage.

"Florida had a lot of people who worked and did not have health insurance through their employer, and that is still the case," said Aetna spokesman Walter Cherniak. "The only difference now is, we have a federal law that says you have to buy something."

Aetna has a walk-in office in downtown Coral Gables where bilingual staff work primarily with Miami-area business owners and insurance agents. "It’s a great location for businesses," said Shannon Roberts Carmona, a Weston-based Aetna executive who oversees medical insurance marketing in Florida. "It has a little bit different flavor from what Florida Blue Cross and Blue Shield does. They tend to put theirs near malls."

Carmona said Florida is a promising growth market for Aetna’s individual medical insurance that "has done very well. It is absolutely one of our top markets," especially for high-deductible plans with low premiums.

"When we first started selling these plans back in 2006, we were selling lower-deductible based plans,’’ Carmona said. “They were in the range of $1,500 to $5,000. Now our best selling plan is a $10,000-deductible plan," she said. "If we would have introduced that in 2006, people would have said, ‘What are talking about? No way!’ ... The environment of Florida has changed because people have lower incomes, and they need low-premium products."

But she also said it’s unclear whether the individual mandate of the Affordable Care Act will lead Aetna to underwrite more individual insurance policies in Florida: "All of those things are under discussion right now. I couldn’t tell you how many or if there will be more."

Among other uncertainties, Aetna and other private insurers have doubt about the future shape of publicly administered medical insurance exchanges. By 2014, the health reform law will require each state to set up an online insurance exchange or, by default, adopt a national exchange. States have until Nov. 16 to notify the federal Department of Health and Human Services of their choice. Gov. Rick Scott has been leading Florida to the default option of adopting a national exchange for medical insurance.