Health insurance is increasingly provided through managed competition, in which subsidies for consumers and risk adjustment for insurers are key market design instruments. We illustrate that subsidies offer two advantages over risk adjustment in markets with adverse selection. They provide greater flexibility in tailoring premiums to heterogeneous buyers, and they produce equilibria with lower markups and greater enrollment. We assess these effects using demand and cost estimates from the California Affordable Care Act marketplace. Holding government spending fixed, we estimate that subsidies can increase enrollment by 16 percentage points (76%) over risk adjustment, while all consumers are weakly better off.