The new national numbers show that nearly 3.3 million people signed up from last Oct. 1 through Feb. 1.
Although Health and Human Services Secretary Kathleen Sebelius says she's encouraged that the sign-up campaign is gaining ground, the government's initial target of 7 million by the end of March still seems like a stretch.
Also, officials are unable to say how many of those who signed up were previously uninsured — the ultimate test of President Barack Obama's hard-fought overhaul.
Beyond the stronger national numbers, the latest report shows huge differences and surprising twists at the state level.
Some Republican-led states whose elected officials strongly oppose the law are keeping pace with monthly sign-up targets that the Health and Human Service Department established in September.
Some states where support for the law is strong are among the worst performers.
The AP's analysis compared the latest cumulative sign-up numbers for each state with targets spelled out in a Sept. 5 memo to Sebelius that the AP obtained months ago.
A dozen states have met or surpassed sign-up targets, including New York, Connecticut, Colorado, Florida, North Carolina and Wisconsin. The first three have Democratic governors. The latter three are led by Republicans, and the federal government has had to take on the role of running the new insurance markets there.
Surprisingly, the worst performers include four jurisdictions where Obama's law has strong support: Maryland, Massachusetts, Oregon and the District of Columbia.