Insurance companies spent millions of dollars trying to defeat the U.S. health care overhaul, saying it would raise costs and disrupt coverage. Instead, profit margins at the companies widened to levels not seen since before the recession, a Bloomberg Government study shows. Insurers led by WellPoint ... recorded their highest combined quarterly net income of the past decade after the law was signed in 2010, said Peter Gosselin, the study author. The industry that was the loudest, most persistent critic of this law, the industry whose analysts and executives predicted it would suffer immensely because of the law, has thrived," Gosselin said. Health insurers contributed $86.2 million to the U.S. Chamber of Commerce to oppose the law after Obama administration officials criticized the [corporations'] plans for enriching themselves by raising customer premiums. Companies are changing their business focus to gain from provisions in the law that will expand the size of Medicaid, the $401 billion government health plan for the poor.