A Commonwealth Fund issue brief finds that the federal high-risk health insurance pool established by the Affordable Care Act is serving its purpose as a bridge program, providing a coverage option for people excluded from the individual insurance market because of a health problem. But the high costs and relatively low enrollment numbers of the Pre-Existing Condition Insurance Plan and the state-run high-risk pools operating in 35 states indicate that high-risk pools in general are not a tenable long-term solution for insuring this population.