The president signed the health care law into law on Tuesday, marking the first time in history that the law has gone into effect in this country.
As of 8:30 a.m.
EST, 1.5 million Americans have signed up for coverage through the ACA.
The law’s main beneficiaries are people who need to pay for prescription drugs or have health insurance through an employer.
But the ACA also includes millions of Americans who are uninsured or underinsured and rely on the law to keep their medical costs down.
More than half of the 1.2 million new people covered by the ACA since the beginning of March are covered by employer-sponsored health insurance, according to a Kaiser Family Foundation analysis.
The law requires employers to offer health insurance to their employees, but the employer must provide coverage that meets minimum standards for coverage and includes essential benefits, such as maternity and hospitalization coverage.
This means the law does not guarantee that all Americans will be covered.
Obamacare has been criticized for its lack of coverage for many groups.
Among them are people with preexisting conditions, who have to pay higher premiums and deductibles than people without them.
And millions of people who would otherwise be eligible for Medicaid, the federal health program for the poor, have not received the funds they need to enroll in it.
Despite its critics, the law is the largest expansion of coverage since World War II.
The new law is set to cover about 12 million people.