Reduce the fraction of people lacking health insurance. You may do this for the uninsured advantaged population (who would purchase commercial insurance or join insurance exchanges) and/or the uninsured disadvantaged population (who would receive Medicaid coverage.)
Consequences: Having insurance makes people more likely to seek preventive and chronic care, which is good from a health standpoint, but has mixed cost effects (more routine visits, more drugs, fewer acute episodes.) Insurance expansion also takes some of the demand load off of Safety Net PCPs, as the newly insured disadvantaged now have the choice of going to a private PCP; this tends to reduce use of the ER for non-urgent episodes, thereby reducing costs. But at the same time, more of the advantaged can now afford to see specialists, thereby increasing various costs.