The changes would triple the number of those children who could take simplified tests.
Roughly 10 percent of special education students — those with the most serious cognitive disabilities — currently can take easier, alternative tests and have the results count toward a school's annual progress goals under the law. Under final rules the administration was to unveil Wednesday, about another 20 percent of children with disabilities would be allowed to take alternative tests.
The No Child Left Behind law is up for renewal in Congress this year, and lawmakers, educators and the public have pushed for many changes. The law imposes sanctions on schools that don't meet certain goals.
The new tests are for children who are not severely disabled but who have been unable to work on grade level because of disabilities, such as some forms of dyslexia.
The new tests won't be as easy as those given to the children already exempted from the regular tests, but they won't be as hard as those given to typical students.
Put together, the change means 3 percent of all children — or roughly 30 percent of all children with disabilities — will be allowed to be tested on standards geared for them.
"No Child left Behind has put the needs of students with disabilities front and center, and this regulation helps continue to drive the field forward in developing better tests for students with disabilities," Education Secretary Margaret Spellings said in a statement.
The department said $21 million would be available to help states come up with the new tests.
The administration is responding to cries from states for more flexibility in how they test special education students.
The 2002 No Child Left Behind law requires that all students be tested in reading and math in grades three through eight and once in high school. When enough students miss annual progress goals, schools can face consequences such as having to overhaul their staffs. Schools can face sanctions even when just one subgroup of children, such as those with disabilities, fails to meet the benchmarks.
That has focused more attention on the progress of children with disabilities, says Doug Fuchs, a professor of special education at Vanderbilt University.
"It includes them in the same accountability framework as kids without disabilities," Fuchs said. "Educators feel as compelled to work with kids with disabilities as they are compelled to work with kids without disabilities."
Several advocacy groups for children with disabilities have raised some concerns about the change, saying they worry it could weaken the promise to leave no child behind.
"Most of these kids surprise us in what they can do," said Katy Neas, a lobbyist for Easter Seals. "When we set the bar higher, more kids do better than we ever thought they could."
Neas said she hoped the federal government would provide states and districts a lot of help in coming up with high-quality tests as well as help in implementing the new policy to ensure the right students are given the right tests.
"That's one place where the department really needs to step up to the plate," she said.
Lawmakers have said there needs to be more flexibility in how special education students are tested and accounted for under the law.
Lawmakers also are considering loosening the testing rules for students learning English and are considering giving states more flexibility in how they measure student progress. Schools that fail to meet progress goals by just a little are treated the same as schools that miss those goals by a lot, something lawmakers say is unfair.