Brian Riess didn't know his Medicaid coverage had lapsed until he was in crisis.

The reapplication process began at a Mesa detox center, and Riess was in line before the state Department of Economic Security office opened Friday to submit the rest of his paperwork and get back on the Arizona Health Care Cost Containment System.

"With this economy," Riess said, "people need help."

State officials are banking on thousands of low-income Arizonans losing their health coverage to help balance the budget for the coming fiscal year.

The stakes have never been higher for more than 220,000 childless adults on the state's Medicaid program. Unless a pending lawsuit or federal intervention prevents an enrollment freeze July 1, once people like Riess fall off the rolls they will no longer be able to get back on, regardless of their income or medical condition.

AHCCCS estimates that 100,000 people will lose coverage in fiscal 2012 if enrollment is capped, saving the state $190 million.

Health advocates say those most at risk are the homeless, mentally ill, those who move frequently and people with sporadic employment who may have become accustomed to "churning" off and on AHCCCS.

"For a lot of this population, they are in survival mode," said Tara McCollum Plese of the Arizona Association of Community Health Centers. "They're basically living paycheck to paycheck, trying to figure out how to get the next meal on the table and pay the rent."

They may only discover that their AHCCCS coverage has lapsed when they become ill or hospitalized, she said.

The health centers have teamed with Keogh Health Connection and several community groups to launch "Don't Get Dropped," a campaign to change long-standing behavior and remind people on AHCCCS and those who work with them to stay enrolled.

Allen Gjersvig, executive director of Keogh, said his agency also is working to get as many people as possible signed up for AHCCCS before the July 1 freeze. During a recent effort at the downtown Phoenix Human Services Campus, volunteers helped 70 people complete AHCCCS applications, roughly half of them renewals.

"We're about helping people get on and stay on," Gjersvig said of Keogh, which was founded in 2003 by former Phoenix CFO Kevin Keogh and his wife, Karlene. "A $4 prescription is a lot more cost effective than an emergency-room visit."

For years, thousands of people each month - sometimes tens of thousands - have churned off and on AHCCCS, which now provides health care for more than 1.3 million Arizonans.

The enrollment freeze is the centerpiece of Gov. Jan Brewer's proposal to cut about $500 million from the state's Medicaid program in fiscal 2012. Her plan also caps enrollment for parents earning above 75 percent of the federal poverty level, effective Oct. 1, which affects about 60,000 parents and would save an estimated $17 million the first year.

The state still needs permission from the federal Centers for Medicare and Medicaid Services to freeze the two programs. Health and Human Services Secretary Kathleen Sebelius has said Brewer can eliminate coverage for these groups without losing federal matching funds because it goes beyond Medicaid requirements. Although federal officials have been tight-lipped, health advocates are assuming that the cuts will win approval.

But the enrollment caps are being challenged in court. In a special action filed last month with the Arizona Supreme Court, three public-interest groups argue the proposed cuts violate the will of the voters and the state Constitution. In 2000, Arizona voters agreed to provide health coverage to everyone earning less than the federal poverty level, which is now $10,890.

Attorneys say they plan to file another action with the state high court or in Superior Court in the next few weeks in hopes of halting the freeze before July 1.

Brewer's plan also would impose mandatory co-payments and fees, limit benefits and further reduce reimbursement rates for health-care providers.

The first reductions took effect May 1, when the state stopped accepting enrollment in the medical-expense deduction program, which temporarily covers medical bills for people who suffer costly health emergencies. Federal officials approved the phase-out, and the program will be eliminated entirely Oct. 1.

Reach the reporter at maryk.reinhart@arizonarepublic.com or 602-444-8603.