WASHINGTON (AP) — A major new survey finds that a growing percentage of Americans gained health insurance as sign-up season for President Barack Obama's health care law drew to a close.

The Gallup-Healthways Well-Being Index finds that the share of adults without health insurance dropped from 17.1 percent at the end of last year to 15.6 percent for the first three months of 2014.

That would translate roughly to more than 3.5 million uninsured people gaining coverage.

The trend accelerated in March, as the enrollment deadline loomed.

The polling firm says the results indicate that the health care law appears to be accomplishing its goal of increasing the share of Americans with health insurance.

Gallup surveyed more than 43,500 adults from January 2 to March 31.