If this is what you’ve been told, you’ve been told wrong.
The law provides that insurance sold to large group markets must have at least an 85% loss ratio, and those serving small groups and individuals must have at least an 80% medical loss ratio (MLR). The loss ratio is the percentage of premium dollar that pays for health care. If loss ratios do not meet these floors, then the shortfall must be refunded to policyholders. The remaining 15 to 20% is available for overhead and profit.
At least 15 states, already have similar regulations, or at least regulations which address MLRs.
In the late 80’s and early 90’s, when I did quite a bit of medical financing consulting, loss ratios hovered around 90% and above. Kaiser was pretty consistent in the 95% range. Over the last 20 years, those ratios have consistently fallen. Now they’re much more typically in the low 80’s and high 70’s. That extra 10 to 15% has all gone to pay exhorbitant overhead and profits, which have grown significantly faster than actual medical costs over the last 20 years.