A proposal from Sen. Ted Cruz may lower premiums for healthy people but could spur more federal spending on tax credits, experts say.

Conservatives have cheered an amendment from the Texas Republican that would let insurers sell plans on the individual market that don’t comply with Obamacare’s coverage requirements, as long as they sell some plans that do. However, the measure is prompting questions about whether it would increase federal spending on tax credits since sicker people would face higher premiums.