Covered California, the health insurance exchange created under the Affordable Care Act, will take the unprecedented step of offering insurance companies financial incentives, and guardrails, to encourage them to continue selling health plans through its program. The agency’s board on Thursday approved a proposal to allow insurers to raise premiums more than normal between 2019 and 2021 if they lose more money than expected in 2018 due to federal policy changes, such as a lack of federal enforcement of the health law’s individual mandate.