A waiting area is filled with applicants waiting to be called during a health care enrollment event at the Bay Area Rescue Mission, Monday, March 31, 2014, in Richmond, Calif. Whether it's a chance for a subsidy or to avoid a tax penalty, Californians are making a last-minute dash to sign up for health coverage. Midnight marks the enrollment deadline under President Barack Obama's health reform law. Covered California, the state's insurance exchange, is reporting a final surge after it already had enrolled more than 1 million people for individual policies. (AP Photo/Eric Risberg)

Jammed phone lines and unreliable websites failed to stop a last-minute rush by hundreds of thousands of Americans trying to sign up for health coverage by the midnight Monday deadline for President Barack Obama's signature domestic policy initiative.

Government officials told The Associated Press late Monday that they were on track to sign up more than 7 million Americans for by the deadline.

The 7 million target, thought to be out of reach by most experts, was in sight on a day that saw surging consumer interest as well as vexing computer glitches that slowed sign-ups on the HealthCare.gov website.

Two confirmed the milestone, speaking on condition of anonymity because they were not authorized to discuss the matter ahead of an official announcement.

About 50 million Americans lacked health care coverage as the law began taking effect, and supporters hope it will significantly reduce the ranks of the uninsured.

But the administration has not said how many of those who already have signed up closed the deal by paying their first month's premiums. Also unknown is how many were previously uninsured—the real test of Obama's health care overhaul. In addition, the law expands coverage for low-income people through Medicaid, the government health care program for the poor, but only about half the states have agreed to implement that option.

Elizabeth Rich helps a man sign up for the Affordable Care Act at Swope Health Services, Monday, March 31, 2014, in Kansas City, Mo. Today is the deadline to sign up for an Affordable Health Care insurance plan however, people who begin the enrollment process but aren't able to complete it by 11:59 p.m. because of a system issue may qualify for a special provision that will allow them to enroll after Monday night. (AP Photo/Charlie Riedel)

The months ahead will show whether the Affordable Care Act will meet its mandate to provide affordable or whether high deductibles, paperwork snags and narrow physician networks make it a bust.

The 2010 passage of the Affordable Care Act has been the No. 1 legislative achievement of Obama's presidency.

Eager to deny Obama any kind of legislative legacy, Republicans have bitterly opposed the law which they say swells big government and represents an unprecedented federal intrusion in the U.S. economy.

After winning control of the House of Representatives in the 2010 elections, Republicans have voted more than 50 times to revoke or seriously undermine the program, widely known as "Obamacare." Those bills have never made it to the floor in the Democratic-controlled Senate.

House Speaker John Boehner said Monday that Republican lawmakers remain committed to repealing Obama's law.

Since the initial enrollment period began in October, millions of Americans have signed up for health insurance through the state and federal exchanges, with many of the policies heavily subsidized to make them affordable for lower -and-middle income Americans.

Elizabeth Rich helps a woman sign up for the Affordable Care Act at Swope Health Services, Monday, March 31, 2014, in Kansas City, Mo. Today is the deadline to sign up for an Affordable Health Care insurance plan however, people who begin the enrollment process but aren't able to complete it by 11:59 p.m. because of a system issue may qualify for a special provision that will allow them to enroll after Monday night. (AP Photo/Charlie Riedel)

On Monday, supporters of the law fanned out across the country in a final dash to sign up uninsured Americans. The HealthCare.gov website, which was receiving 1.5 million visitors a day last week, had recorded about 2 million through noon (1600 GMT) Monday.

At times, more than 125,000 people were simultaneously using the system, straining it beyond its previously estimated capacity. People not signed up for health insurance by the deadline, either through their jobs or on their own, were subject to a federal tax penalty—a threat that helped drive the rush.

The federal website operating in 36 states stumbled early—out of service for nearly four hours as technicians patched a software bug. An afternoon hiccup temporarily kept new applicants from signing up, and the process slowed further as the day wore on. Overwhelmed by computer problems when launched last fall, the system has been working much better in recent months, but independent testers say it still runs slowly.

The administration announced last week that people who started applying for health insurance but were not able to finish before Monday's enrollment deadline will get extra time.

The law's supporters are already trying to make the next open enrollment season, staring Nov. 15 more consumer friendly.

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