WASHINGTON - State officials and advocates for the poor are asking the federal government for greater flexibility in enforcing a new law that requires Medicaid enrollees and applicants to verify their citizenship and identities beginning July 1.

Those who can’t produce a U.S. birth certificate, passport, naturalization certificate or other acceptable documentation could lose or be barred from coverage under Medicaid, the joint state and federal health plan that serves more than 50 million low-income adults and children.

The new law, included in the Deficit Reduction Act that President George W. Bush signed into law in February, was authored by Republican Reps. Charles Norwood and Nathan Deal, both of Georgia. It’s designed to prevent undocumented immigrants from receiving taxpayer-funded health care that’s slated for U.S. citizens and other qualified recipients.

The Congressional Budget Office estimates that the law will save $220 million between 2006 and 2010 and purge 35,000 people from Medicaid rolls by 2015.

But experts fear that rightful Medicaid enrollees who can’t produce the needed documents will lose their coverage as well. State officials worry that the new law will create a massive administrative burden and confuse beneficiaries.

The federal Centers for Medicare and Medicaid Services is responsible for raising public awareness about the new law and for drafting guidelines on what alternative documents, if any, can be used to validate citizenship and to prove identity. But with less than a month before the law takes effect, the agency has done neither.

States want the federal government to accept as many records as possible in verifying citizenship and identity, including driving, birth and school records, military records, voter registration cards, and Native American tribal records. And they want to check Medicaid records electronically against records from other programs to streamline the verification process.

Stan Rosenstein, California’s Medicaid director, also wants to use signed personal affidavits for young children and for certain adults on Medicaid who can’t produce or don’t have the required documents.

"We want to use as many alternative sources as possible to verify citizenship," Rosenstein said.

South Carolina’s Medicaid officials issued their own rules Thursday on what documentation is acceptable to meet the new requirement. "The feeling here was that if we waited for" federal officials "to issue guidelines without starting to look into this ourselves, then we would maybe be putting our beneficiaries at risk," said Jeff Stensland, a spokesman for the South Carolina Department of Health and Human Services.

Mark McClellan, the federal Medicaid administrator, said Friday that implementation guidelines and other support materials would be released very soon. He said the agency is working with state Medicaid directors on their requests for flexibility in accepting alternative documents. The agency is also trying to provide additional time for people to locate their records.

"We know that for some people it’s going to take a little time, and we want to be able to account for that," McClellan said.

The agency could have released implementation guidelines sooner, McClellan said, but it chose to wait to address a myriad of concerns.

Only U.S. citizens, U.S. nationals and qualified immigrants are eligible for full coverage under Medicaid. Forty-seven states accept signed declarations from Medicaid applicants as proof of U.S. citizenship, according to a 2005 study by the Health and Human Services inspector general’s office.

Most states require further documentation only if a Medicaid application seems questionable.

But in 2003, the most recent year studied, 27 of the 47 states didn’t verify the personal declarations as federal regulations require, the report said. And because Medicaid accepts mail-in applications, the validity of the statements can’t always be thoroughly checked. The report found that these problems "could allow false statements of citizenship to go undetected."

The report urged Medicaid to make changes, such as strengthening reviews of citizenship declarations, but didn’t call for the changes being enacted.