But the companies' profits still represent a miniscule percentage of the $2.5 trillion Americans spend every year on health care.
"Insurance company profits in the large picture have very little to do with the overall rising cost of health care," said health care expert Henry Aaron, a senior fellow at the Brookings Institution.
Carroll and others pointed out that the profit margins the health insurance companies report -- often below 5 percent -- pace some industries and lag behind many others.
"From a net margin basis, it's not that much," said Steve Shubitz, an analyst at Edward Jones. "The bottom line is any business needs to make money. That's why you're in business."