After a computer glitch was patched up, supporters of President Barack Obama's health care law were out in force Sunday trying to get uninsured people signed up by the official deadline for 2015 coverage.

The effort had the trappings of a get-out-the-vote drive, with email reminders, telephone calls and squads of community-level volunteers.

"You can't avoid it: TV, radio, church, wife, kids, co-workers," said Ramiro Hernandez, a previously uninsured truck repair shop owner who enrolled himself and his family in Joliet, Illinois, on Saturday.

Technicians anxiously monitored the HealthCare.gov website for any new bugs. The administration provided no numbers on weekend sign-ups.

New York, which is running its own insurance market, announced a two-week extension for anyone who has already started an application. Federal officials had said they, too, would allow extra time for people to finish in the 37 states served by HealthCare.gov. But officials have not said how long that grace period will be.

The health law offers subsidized private coverage to people without access to it on the job. Health and Human Services Secretary Sylvia M. Burwell has set a nationwide target of 9.1 million people enrolled and paying premiums in 2015. Some experts say that's too modest. Nonpartisan congressional analysts have estimated 12 million people will sign up in the new insurance markets.

"Overall, we are really pleased with turnout," said John Gilbert, national field director for Enroll America, a nonprofit that works closely with the administration. "We expect that this will be a big number here at the end."

Officials held their breath Saturday when a technical problem knocked out the income verification system. Gilbert said consumers were getting a yellow screen that would not let them continue. Website woes made headlines last year, a major embarrassment for a tech-savvy White House.

Income verification, which the IRS handles, is crucial to the application process. The subsidies that most people get to help pay their premiums are based on how much they make. The problem popped up late in the morning.

"At first it seemed like no one could get through," said Gilbert. "Then it started improving. It improved throughout the afternoon and then it was completely resolved."

Consumers who got snagged by the glitch will have extra time to finish their applications.

The sign-up deadline in states served by the federal marketplace is 2:59 a.m. Eastern time Monday. Some states running their own exchanges have different deadlines.

This year there's a big question mark hanging over the enrollment drive, and it has nothing to do with technology.

Early next month, the Supreme Court will hear arguments on another challenge to Obama's law. The plaintiffs in the case say the literal wording of the law only allows the federal government to offer subsidies in states that set up their own insurance markets. Most states have not done so.

If the court sides with the plaintiffs, millions of people would lose financial assistance, and most of those would drop their coverage.