Insurers with decades of experience and brand-new plans underestimated claims costs.
These exemptions permit them to share industrywide information on claims costs and project future costs.
Insurers acknowledge that they consider several factors besides claims costs in setting prices for doctors.
So the cost of replacing stolen cars, which accounts for a quarter of insurers' claims costs, has fallen.
That study reports average claims costs per member per month for what it calls the "pre-A.C.A".
Revenue from premiums rose 8percentto to $17.17 billion, while claims costs fell 36percentto to $10.7 billion.
"Until firm action is delivered on whiplash and the compensation culture, claims costs will continue to rise.
Aetna raised its profit forecast for the full year, outperforming some rival health insurers that cut their earnings expectations because of rising medical claims costs.
"Insurance premiums are based on a number of different data, including the historic claims costs swiftcover.com has witnessed for specific occupations.
"This means that we do not provide cover to some professions that, according to that data, have a higher level of claims costs.
More generally, it says, the new federal insurance standards, which increase protections for consumers, "are expected to lead to aggregate increases in claims costs in many states".
