States that are implementing the Common Core academic standards and new standardized tests in public schools can have an additional year before they have to use those student test scores to decide pay and job security for teachers, Education Secretary Arne Duncan said Tuesday.

The U.S. Education Department will decide on a case-by-case basis whether to grant the extensions for using new tests as a factor in personnel decisions, Duncan said. Some states already link the tests to teacher evaluations, while others had committed to using test scores in personnel decisions during the next two years.

Duncan also said that states that “field test” new assessments based on the new standards next year won’t have to use those test scores to measure overall school performance to meet federal guidelines. Instead, states can choose to freeze the accountability status of its schools for a year — meaning that the scores will not adversely affect the school districts — but they would still be required to take corrective action in the weakest schools.

The move would allow schools to avoid “double-testing” or giving students both the old state tests and the new Common Core exams during the same academic year.

Duncan is offering that leeway to 37 states and the District, which have received waivers from the Obama administration on most aspects of No Child Left Behind, the main federal education law.

Teachers groups said the decision was prudent in the face of new standards that have barely made their way into classrooms nationwide, while Republican legislators and reformers slammed it as a delay in accountability.

In a call with reporters, Duncan said the additional time is not a delay.

“We’ve heard from some teachers, state chiefs and others about the need to give teachers more time to learn the standards and integrate them into their practice before they’re held accountable,” Duncan said. “We will not have a pause. Those time frames will absolutely remain the same. The need for change frankly is too urgent.”

To get the waivers from No Child Left Behind, states had to agree to adopt new academic standards in K-12 reading and math that would ensure students graduate ready for college or careers. Most states chose to adopt the Common Core standards in reading and math, which are rolling out in 45 states and the District.

States are required to develop new standardized tests that relate to the new standards and administer them annually to students from third through eighth grades and once in high school. New York and Kentucky already have implemented the new tests, but many states were aiming to roll out the new standards in 2013-14 and launch the new tests in 2014-15.

In recent months, teachers and state education officials have pressed the Obama administration for relief, saying that it was unfair for teachers to be judged by student scores on new tests based on new academic standards.

“If we say the Common Core is really important and it’s going to change the DNA of learning and it’s what kids need for the jobs of today and tomorrow, then we have to give teachers the time and the wherewithal to actually do it and get it right,” said Randi Weingarten, president of the American Federation of Teachers, who in April called for something similar to what Duncan announced Tuesday. Dennis Van Roekel, president of the National Education Association, called it “a step in the right direction.”

But critics, including Republican leaders in Congress and a small group of education officials known as “Chiefs for Change,” slammed the plan as a step backward from accountability.

“We will continue to strive for full implementation of all accountability measures that have proven successful in preparing our children for the future,” said Tony Bennett, Florida’s education commissioner and a leader of Chiefs for Change.

Sen. Lamar Alexander (Tenn.), the ranking Republican on the Senate Committee on Health, Education, Labor and Pensions, said the maneuver is another example of federal overreach.

“If anyone is looking for further proof that our education system is congested with federal mandates, the education secretary is now granting waivers from waivers,” Alexander said. “The waivers were meant to give states relief from unworkable requirements, but the education secretary put so many conditions on states that now the waivers are unworkable.”

Maryland State Superintendent of Schools Lillian Lowery said she expects that the state will ask the federal government to allow it to wait until 2016 to tie test scores to personnel decisions and to freeze the accountability status of its schools next year. A spokeswoman for the District said it hadn’t decided whether to apply for flexibility. Virginia did not adopt Common Core standards.