Covering adults through the State Children’s Health Insurance Program tends to be somewhat more expensive than covering children through the program.

Researchers at the U.S. Government Accountability Office have reported that finding in an study prepared at the request of Sen. Charles Grassley, the most senior Republican on the Senate Finance Committee.

GAO researchers looked at SCHIP coverage data for the 10 states that have been covering non-pregnant adults through SCHIP.

Only about 349,000 of the 4.5 million SCHIP participants were non-pregnant adults in 2006, but about 40% of all individuals covered by SCHIP in the 10 states studied were non-pregnant adults, GAO officials estimate.

Some states used SCHIP to cover the parents of children enrolled in the program, and some used SCHIP to cover childless, non-pregnant adults.

In the states that provided coverage themselves, rather than subsidizing private carriers, expenditures on each parent in SCHIP ranged from 41% to 135% higher than expenditures on each child in the program, GAO officials estimate.

Monthly expenditures in the “direct coverage” states averaged $144 per child, with a range of $95 to $201.

For parents in the direct coverage states, monthly expenditures averaged $260 and ranged from $222 to $333.

In states that provided subsidies for parents, rather than direct coverage, monthly expenditures on parents ranged from $64 to $213.

A copy of the GAO SCHIP report is available