JUDY LIN, Associated Press

SACRAMENTO, Calif. (AP) — The federal health care overhaul is providing coverage for millions of Americans, but it has only chipped away at one of its core goals: to sharply reduce the number of people without insurance.

President Barack Obama announced last week that 8 million people have signed up for coverage through new insurance exchanges, but many barriers remain.

Questions of affordability, eligibility, immigrant access and the response from employers and state legislatures — obstacles that existed before the Affordable Care Act took effect — mean considerable work remains to make a larger dent in the uninsured population.