It may just be the start of a new trend. The uninsured rate dropped modestly this month as expanded coverage rolled out under President Obama's health care law, a major survey released Thursday has found. Here's a look at the findings of the Gallup-Healthways Well-Being Index:

Uninsured: The uninsured rate for U.S. adults dropped by 1.2 percentage points in January, to 16.1 percent. That would translate to roughly 2 million to 3 million people gaining coverage.

For unemployed: The biggest change was for unemployed people, a drop of 6.7 percentage points. That was followed by a 2.6 percentage-point decline for nonwhites. Traditionally both groups are far more likely to be uninsured than the population as a whole.

For young adults: The survey found no appreciable change among young adults ages 18-34. Members of that coveted, low-cost demographic have been ambivalent about signing up so far.

For women: Women saw a decline of 1.9 percentage points, about three times greater than the 0.6 percentage-point drop for men. Uninsured rates also fell all along the income ladder, with those making $36,000-$89,999 seeing the greatest drop, 1.8 percentage points.

Medicaid: Medicaid sign-ups are also rising. That's partly because of a program expansion accepted by half the states and partly as a consequence of previously eligible but unenrolled people now forced to obtain individual coverage.

The back story: Major elements of the health care law took effect with the new year. Virtually all Americans are now required to get covered or risk fines.

What's next: Open enrollment season ends until March 31. Frank Newport, Gallup's editor-in-chief, said it could take a calendar quarter — three months — to discern a full trend.

Reaction: The White House called the poll good news. "It shows that the law is working," said David Simas, a senior adviser.

The office of Senate Minority Leader Mitch McConnell, R-Ky., pointed out that according to the poll, the adult uninsured rate is about the same now as when Obama took office in 2009. It has gone as high as 18.6 percent during his term.

About the poll: The poll combines the scope and depth found in government surveys with the timeliness of media sampling. Pollsters interview 500 people a day, 350 days a year. The survey can be an early indicator of broad shifts in society. The health care results were based on more than 9,000 interviews, about nine times as many as in a standard national poll. The survey was based on telephone interviews from Jan. 2-19 with a random sample of 9,145 adults aged 18 and older in all 50 states and the District of Columbia. For results based on the total national sample, the margin of sampling error is plus or minus 1 percentage point, larger for subgroups.

Gallup's numbers are not comparable to various figures cited by the Obama administration, estimates that have ranged to more than 9 million people benefiting. For starters, the administration's numbers include children as well as adults. They combine people buying coverage in the new insurance exchanges, Medicaid enrollees, and young adults who can stay on a parent's plan until they turn 26. But the administration doesn't tease out those who were previously uninsured.

Associated Press