An individual mandate will have a negligible effect on aggregate national health spending but will increase government spending on Medicaid and premium subsidies:

• Aggregate national health spending will increase by $7 billion to $26 billion, depending on the design of the mandate; this represents an increase of 0.3–1.2 percent of total spending and is indistinguishable from zero.
• Under an individual mandate, Medicaid expenditures would increase by up to $25 billion (about 7.6 percent), and overall government spending in health care would increase $12 billion to $62 billion (1.2–6 percent), depending on the design of the mandate
• Government cost per newly insured person is similar at all nonzero subsidy levels and declines as the size of the penalty increases.
• In general, other researchers who have used microsimulation methods to estimate the effect of an individual mandate on spending have estimated substantially larger increases than we did.