The 10-year old, extremely popular, and reasonably successful State Children's Health Insurance Program (SCHIP) expires in six weeks. Congress and the White House must agree on a reauthorization bill, and so far the parties are far apart.

Here are some key resources to understand the radically different House and Senate bills. Most notably, the House bill is far more expansive and expensive. While the bill is ostensively to reauthorize and expand SCHIP, the House bill would also make dozens of significant changes to both Medicare and Medicaid. The more moderate Senate bill focuses on renewing SCHIP, providing additional federal dollars to cover more children, and proposing higher tobacco taxes to offset the new federal SCHIP costs.

Children's Health Insurance Program Reauthorization Act (Senate Bill 1893):

The Senate bill, called the Children's Health Insurance Program Reauthorization Act of 2007, would extend coverage to an additional 2.2 million children. This is a net figure. An estimated 4.5 million kids would move to SCHIP coverage, but CBO estimates that 1.7 million of these would move from private insurance to SCHIP because of crowd-out and another 600,000 would move from Medicaid to SCHIP. Because of interactions between Medicaid and SCHIP coverage, the Senate bill would increase add, net of crowd-out, about 1.5 million kids to Medicaid.

To sum up, the Senate approach would provide SCHIP or Medicaid health coverage to a net 4 million uninsured children. But about 2.1 million privately insured children would have to move from their existing private insurance coverage to taxpayer financed care. To read the Congressional Budget Office's cost and enrollment estimates for the Senate bill, click here.

Children's Health and Medicare Protection Act (HR 3162):

Based on CBO projections, the House bill, called the Children's Health and Medicare Protection Act, would increase coverage for a net 5 million children. About 3.1 million uninsured kids would be newly covered by Medicaid and about 1.9 million by SCHIP.

Again, because government financed health coverage "crowds out" private coverage, the House bill would cause about 2.5 million insured children to lose existing private coverage and move to taxpayer-funded coverage. Click here to read CBO's cost and enrollment estimates for the House bill, including the bill's many unrelated changes to Medicare and Medicaid.

Before closing, it's important to note that whatever Congress does with SCHIP reauthorization, the program is highly dependent on subsequent state policies, including appropriation of state budget dollars. And several aspects of the Congressional SCHIP proposals would hurt state finances and restrict flexibility, making children's health coverage at the state level more costly and complex.