2014 has been a decidedly busy year for Obamacare. In January, four years after Congress passed the law, its biggest provision — an insurance expansion to cover millions of Americans — took effect.

This tweet, from Kaiser Family Foundation's Larry Levitt, is an excellent summary of what's different about the United States one year into the Affordable Care Act:

ACA by the numbers: 10 m ? in uninsured Benchmark premiums ? 2% on avg 6.7 m in marketplaces 9.7 m ? in Medicaid 3.8 m in the Medicaid gap — Larry Levitt (@larry_levitt) December 29, 2014

In short, millions more people have health insurance than did at this point last year. More people gained coverage through Medicaid, the public program that covers low income Americans, than through private coverage. And premiums increased at relatively slow rates. Obamacare seems to have done what it was supposed to: increased the number of Americans with insurance coverage.