Designing health insurance market constructs for shared responsibility: insights from California.

Moving toward universal participation in health insurance using a "shared responsibility" approach requires new, more accessible, and more efficient ways for people who are not offered employer coverage to obtain coverage. California's recent health reform plan-which failed to pass-incorporated individual market reform and choice-pool constructs to achieve critically important risk spreading, assure solvency, and reduce cost shifts. These measures, as well as the considerations that led to their design, offer important insights for health reform at the federal level.