State health exchanges in uncharted waters.

• Position: STATESTATS - Patient Protection and Affordable Care Act

Health insurance exchanges for all 50 states ramped up in January as the Affordable Care Act continued its rollout. Seventeen states have their own exchanges. The federal government, in varying degrees, runs the exchanges in the remaining states, which have the option to transition to a state exchange after this year. Despite October's rocky launch of the federal enrollment website, HealthCare.gov, roughly 2.1 million Americans had signed up for insurance on state or federal websites or by manually completing applications by January 1, the day coverage began.

A goal of the law is to offer affordable health insurance for the 44 million uninsured Americans through these exchanges, also called marketplaces, where individuals can shop for insurance and find out if they're eligible for federal financial assistance. Small businesses can also buy group health insurance at the exchanges through the Small Business Health Options Program (SHOP). State sites generally have outperformed the federal one; the exchanges in Connecticut, Kentucky, Rhode Island and Washington have done especially well.

Numerous states that accepted federally run exchanges often did so in protest of the law, which policymakers labeled costly, irresponsible, unworkable or a breach of states' rights. About half also declined federal money to expand Medicaid.

Who Qualifies for Subsidies?

In most states, people with incomes in these ranges qualify for tax credits to help lower their monthly premiums---or for other financial...