A Michigan-based firm says it experienced health cost savings after investing in a private exchange and defined-contribution plan designed by three Blue health insurers to simplify insurers’ health benefit offerings.

Four of the nation’s largest health insurers had “dramatic reductions” in their claims payment denial rates since last year, according to new American Medical Association research.

Increasingly cast as the villain in the nation’s rising cost for health care, five of the nation’s largest health care insurers met with the Obama Administration to argue that they are bit players in a much larger production.

The nation’s eight largest health insurance companies collectively lost 836,000 members in the first six months of the year, as commercial enrollment sagged.