Federal officials cleared the way Friday for Arizona to bar thousands of low-income residents from seeking Medicaid coverage in the next year as the state tries to close a budget shortfall projected at roughly $1 billion.

The partial freeze that will prevent adults without children from either enrolling for the first time or re-enrolling in the Medicaid program if they left previously is set to begin next Friday. It had initially been scheduled to begin a week earlier but the state needed federal clearance to implement the program, and federal officials weren't yet ready Thursday to act on the latest version submitted earlier this week.

Monica Coury, assistant director of the state's Medicaid program, known as the Arizona Health Care Cost Containment System, said that federal clearance of the implementation plan would mean the freeze will take effect July 8. State officials need the time to make preparations that include changing computer programs, she said.

Estimates on the number of low-income Arizonans affected in the next year because of the July 8 freeze and a smaller one for parents planned to take effect Oct. 1 for another eligibility category range from 130,000 to 150,000. The state's Medicaid now covers approximately 1.3 million.