Medicare Map Favors Aetna

While national players tend to dominate that particular market, at least one regional company -- Humana (HUM Quote) -- seems to face exposure there.

Finally, Hojlo pointed to the Arizona and Pennsylvania/West Virginia regions as possible areas of concern. He called Arizona -- with its exploding senior population -- "less problematic" than Nevada even though its own proximity to California seemed to drive its bids lower as well. Elsewhere, he compared challenges in Pennsylvania and West Virginia to those that make Ohio especially troublesome.

Along with PacifiCare and some national companies, both Health Net and Humana rank as important players in Arizona. Meanwhile, Coventry Health Care (CVH Quote) stands out as one of the largest players in the Pennsylvania/West Virginia market.

"We still remain positive on the Medicare market opportunity for all of our outperform-rated companies (Aetna, Amerigroup (AGP Quote), PacifiCare, UnitedHealth, WellChoice (WC Quote) and WellPoint)," he concluded. "We simply think that we are correct in maintaining relatively conservative Part D contribution assumptions in our 2006 projections ... and also correct in our belief that the major national health plans will be the Medicare winners in the long run."