California, the nation's most populous state, risked losing nearly $800,000 in funding this year, but a 2008 estimate put the cost of complying at $32 million.
The five states that have given up on the program still have the option to reapply for the withheld money. The 29 states that are in partial compliance have asked to have their withheld money released to help them meet conditions of the law.
Richard Kishur, an Oklahoma City counselor who has worked with sex offenders for more than 30 years, said his biggest reservation was that the law categorized offenders by the crime they commit, not the risk they actually pose.
"What we need to do is be rational about it and apply resources to people who are dangerous and quit wasting our money and time on people who aren't dangerous," Kishur said. "The law is making a lot of people's lives miserable because a lot of it should apply to psychopathic murderers instead of people who are situational and opportunistic offenders who aren't real likely to offend."
Proponents of the law had hoped it would ease the risk that states with less-stringent registration would become havens for sex offenders.
Mark Pursley, who managed sex offenders for nearly a decade at the Oklahoma Department of Corrections, recalled hearing offenders discuss moving to states with relaxed rules.
"They were very in tune with what requirements were in different states, and they would frequently migrate to other states," said Pursley, who is now retired.
James Womack, a convicted sex offender from Oklahoma who now works for a nonprofit agency that helps recently released felons, said he understands the need for consistent registration rules. But he cautioned that registration alone will not stop them from reoffending.
"It doesn't do anything to stop crime," said Womack, who was convicted in 2005 of indecent liberties with a child and served nearly two years in prison. "A true pedophile, if they're going to offend, they're going to offend, whether or not they live one mile or 10 miles from a school."