The U.S. Education Department has reminded Colorado and 12 other states that federal funding is still tied to testing students on math and language arts, despite the end of No Child Left Behind.
The department asked states with large numbers of students skipping the tests how they plan to do better.
A letter to state school chiefs last month noted that the nation's new education law still requires testing for grade 3-8 students -- and that states falling short of 95 percent participation risk losing funding.
The states were asked for corrective plans. Responses reviewed by The Associated Press show many plans include outreach to parents and downgrading school ratings. None appear to carry financial consequences.
In addition to Colorado, the letters went to California, Connecticut, Delaware, Idaho, Illinois, Maine, New York, North Carolina, Oregon, Rhode Island, Washington and Wisconsin.