Medical loss ratio regulation under the Affordable Care Act.

The minimum medical loss ratio (MLR) regulations in the Affordable Care Act guarantee that a specific percentage of health insurance premiums is spent on medical care and specified activities to improve health care quality. This paper analyzes the regulations' potential unintended consequences and incentive effects, including: higher medical costs and premiums for some insurers; less innovation to align consumer, provider, and health plan incentives, less consumer choice and increased market concentration; and the risk that insurers will pay rebates if claim costs are lower than projected when premiums are established, despite the regulations' permitted "credibility adjustments." The paper discusses modifications and alternatives to the MLR regulations to help achieve their stated goals with less potential for adverse effects.