Bernice Todd's Choctaw family roots are sunk deep in the soil of Oklahoma, a state whose very name is Choctaw for "red people." But in the middle of a debilitating battle with cancer, Todd, a 39-year-old who cleans homes at a trailer park and baby-sits for a living, lost her state Medicaid health care coverage because, although she's a Native American, she could not prove she is a U.S. citizen.

While Todd's case is rich in irony, she is one of tens of thousands of Americans who are falling victim to a new federal rule—aimed at keeping illegal immigrants off the Medicaid rolls—requiring that recipients prove their citizenship and identity with documents many don't have.

States have always been required to check a Medicaid applicant’s eligibility, which includes citizenship. But a July 2006 rule, enforced by the federal Centers for Medicare & Medicaid Services (CMS), now demands specific documents as proof, such as a passport or a birth certificate, driver's license or military record. States face fines if they don't comply.

The rule, which neither CMS nor the Bush administration requested, was adopted by the Republican-dominated Congress in 2005 despite the fact that there was no evidence that undocumented immigrants were falsely claiming U.S. citizenship to get Medicaid.

"This rule was the answer to a problem that really doesn’t exist," says Donna Cohen Ross, an analyst with the Center on Budget and Policy Priorities in Washington, a nonpartisan research organization.

In fact, the year the rule was passed, Mark McClellan, then the administrator for CMS, said that a report by the CMS inspector general did "not find particular problems regarding false allegations of citizenship, nor are we aware of any." Most states agreed with that assessment.

"In 2007 we added $1 million to our budget just to handle the cost of this new rule when we had absolutely no indication there was a problem with illegal immigrants getting Medicaid in Kansas," says Andrew Allison, Kansas Medicaid director and deputy director of the state Health Policy Authority.

Just a small fraction of America's health care spending is used to provide publicly supported care to the nation's undocumented immigrants, according to a RAND Corporation study issued today.

Overall, immigrants to the United States use relatively few health services, primarily because they are generally healthier than their American-born counterparts, according to the study by the nonprofit research organization.

So far, he says, Oklahoma has uncovered no illegal immigrants on its rolls. And Arizona, where immigration is a huge issue, has filed two reports since the rule went into effect, each saying the state uncovered "zero" illegal immigrants among its 1 million Medicaid recipients. Kansas has found one illegal immigrant on its Medicaid rolls.

A U.S. Government Accountability Office survey of the states last year found that that the requirement caused eligible U.S. citizens to lose Medicaid coverage while increasing administrative costs. A close analysis of six states, the report says, showed that for every $100 spent to implement the rule, only 14 cents was saved.

In fact, nationwide the rule has added millions of dollars in administrative costs.

So, because we were worried that foreigners might be using up our precious medical supplies (which was one of the top concerns over immigration on this poll, and of course isn't true), we have adopted a "solution" that instead deprives thousands of actual citizens of health care. Brilliant.