WASHINGTON (AP) — The Affordable Care Act has yet again beaten predictions of its downfall, as government figures released Wednesday showed unexpectedly solid sign-ups for health coverage next year.

The Centers for Medicare and Medicaid Services said nearly 8.5 million people had enrolled as of last Saturday's deadline, with about a dozen states, including California and New York, still left to report. The preliminary number was down about 4 percent, when a much bigger loss had been expected.

Different factors combined to make for an unpredictable sign-up season this year for former President...