Washington is set to become the first state to enter the private health insurance market with a universally available public option. A set of tiered public plans will cover standard services and are expected to be up to 10% cheaper than comparable private insurance, thanks in part to savings from a cap on rates paid to providers. But unlike existing government-managed plans, Washington’s public plans are set to be available to all residents regardless of income by 2021. The Legislature approved the plan last month, and Gov. Jay Inslee is scheduled to sign it into law Monday. The move thrusts...