From this:

Hundreds of thousands of illegal immigrants could receive health care coverage from their employers under the [House and Senate] bills winding their way through Congress, despite President Obama's explicit pledge that illegal immigrants would not benefit... The House bill mandates, and the Senate bill strongly encourages, businesses to extend health care coverage to all employees. But the bills do not have exemptions to screen out illegal immigrants... A rough estimate by the Center for Immigration Studies suggests that the practical effect of the mandates would be that about 1 million illegal immigrants could obtain health insurance coverage through their employers...