Washington ? Skeptical states are shoving aside millions of federal dollars for abstinence education, walking away from the program the Bush administration touts for slowing teen sexual activity.

Barely half the states are still in, and two more say they are leaving.

Some $50 million has been budgeted for this year, and financially strapped states might be expected to want their share. But many have doubts that the program does much, if any good, and they’re frustrated by chronic uncertainty that it will even be kept in existence. They also have to chip in state money in order to receive the federal grants.

Iowa Gov. Chet Culver, a Democrat, made his decision to leave based on the congressionally mandated curriculum, which teaches “the social, psychological and health gains of abstaining from sexual activity.” Instructors must teach that sexual activity outside of marriage is likely to have harmful psychological and physical effects.

“It was just too strict,” said Emily Hajek, policy adviser to Culver. “We believe local providers have the knowledge to teach what’s going to be best in those situations, what kind of information will help those young people be safe. You cannot be that prescriptive about how it has to be taught.”

A federal tally shows that participation in the program is down 40 percent over two years, with 28 states still in. Arizona and Iowa have announced their intention to forgo their share of the federal grant at the start of the fiscal year that begins Oct. 1.

The program was created by Congress in 1996 as part of welfare reform.

Since 2002, lawmakers have approved 19 short-term extensions – usually for three or six months at a time. But on three occasions, the program was extended for just a few days.

Whatever state officials think of the program’s aims, that’s not the kind of bureaucratic consistency they need to budget for employees and to put contracts out to bid.

“The funding stream became inconsistent. We didn’t know from one quarter to the next whether we’d be getting the rest of the money,” said Elke Shaw-Tulloch of the Idaho Department of Health and Welfare. “We got to the point where we didn’t have any infrastructure to put the money to use. At the same time, there was mounting evidence the abstinence programs weren’t proving to be effective.”

Throw in a rising pregnancy rate among 15-19 year-olds in Idaho – 2,543 pregnancies in 2006 compared with 2,396 in 2004 – and state officials decided last summer it was time to get out.

Stanley Koutstaal, the federal official who oversees the abstinence-only program at the Administration for Children and Family Services, notes that more than half the states still choose to participate. “Obviously, many states still find it valuable and have adopted it as their approach to addressing the sexual activity of teens,” he said.

He called for long-term reauthorization of the block grants so that states and their contractors can be more certain about the future and can plan accordingly.