Legislation to provide the $400 million federal share over 10 years was passed by the Senate before Congress recessed in July.

The federal share was 75 percent or less, as agreed.

With the exception of the indexation component, the federal share has already been used in full (as of September 2010).

Take a state whose federal share is 50 percent.

Medicaid is expected to cost $277 billion this year, of which $158 billion is the federal share and $119 billion comes from the states.

Congress appropriated $289,000 for the federal share of the study's costs in FY2010.

In poor states the federal share of Medicaid spending is nearly 80 percent.

Of that, nearly half is provided by the federal Government, but for theater and opera the federal share rises to 70 percent.

As a result, the federal share must be appropriated annually through Congress.

The federal share of funding would be 90 percent in the first year, slowly declining to about 25 percent after a decade.