The federal government is easing some teacher quality reporting deadlines.
Rural and science teachers will get extra time to prove their qualifications.
Thousands of teachers in rural areas now have until spring 2007 to show they are qualified in all subjects they teach and highly qualified in at least one.
"Some unique challenges are faced by science teachers and some current teachers who have been teaching a subject for many, many years and developed a lot of expertise during that period of time," said Dr. Rod Paige, U.S. Secretary of Education. "These policies will help us keep our promise to provide every child with a great teacher, because we know how vital it is. The teacher is the single best insertion point to make a difference in the life of children."
Paige said the intent of "No Child Left Behind" is to have accountability standards in place, but it is also flexible on some points.
The change is expected to affect at least one third of school districts, especially those where teachers are asked to teach more than one subject.