When the past school year began, four states were in danger of losing their waivers from aspects of the law. But only one has actually lost the flexibility Duncan began promoting in 2011: Washington.
The three others - Oregon, Kansas and Arizona - appear to be on the path to resolving their differences with the federal government.
The waivers are considered a temporary measure while Duncan works with Congress to rewrite the No Child Left Behind law.
Members of both parties agree the law - which required every child in the nation to be reading and doing math at grade level by 2014 - is broken, but they have been unable to agree on a fix.
While it has been praised for focusing on the performance of minorities, low-income students, English-language learners and special education students, the education law has led to a number of schools being labeled as "failing" and some say it encourages instructors to teach to the test.
Under the federal waiver system, states can create their own accountability process, while they wait on Congress to come up with a permanent solution.
The U.S. Department of Education describes its requirements for the states as follows: making rigorous and comprehensive plans for improving learning for all students, closing achievement gaps, increasing equity and improving the quality of instruction.
The fine print - and what some would call independence or stubbornness - is what tripped up Washington state and put it back under the 2001 federal education law's requirements.
Duncan has told Washington the state can have its waiver back anytime it wants to change its teacher-evaluation system to include student achievement on statewide academic tests as a factor in judging teachers. But the state teacher's union and lawmakers on both sides of the aisle say the federal government is asking too much.
Washington schools chief Randy Dorn doesn't agree. He will continue working to convince the state Legislature to change Washington's teacher-evaluation system, a goal he failed to achieve this past year, Dorn said.
"The disappointing part to me is that I thought we had a great solution," he said.
Dorn said he didn't think the proposed change to state law - going from optional use of statewide tests to mandatory use in teacher evaluations without a specific goal on how big a factor the tests would be - wouldn't have changed the way teachers are evaluated.
Principals are already looking at student data and discussing it with teachers and then working together to set goals, Dorn said. He doesn't believe making this the law instead of just the practice would change much.
The Washington Education Association argues that lawmakers did the right thing in rejecting what it calls Duncan's inflexible and bureaucratic demands. Union spokesman Rich Wood said Duncan earlier this year praised Washington state for its school improvement, which it accomplished without meeting his demands.
Dorn said he believes he has a better chance of getting cooperation from the Legislature this year, because it will be wrestling over the state's biennial budget starting in January. That situation will give lawmakers dollars to trade as well as philosophies, he said.
Oregon, Kansas and Arizona are all finalizing new teacher-evaluation systems to meet Duncan's requirements for keeping their state waivers. Three states - Illinois, Wyoming and Iowa - have applied for waivers and are awaiting a response. Five do not have waivers but could someday: California, Montana, North Dakota, Nebraska and Vermont.