Twelve and 13-year-olds accused of serious crimes will now be dealt with by Youth Court.
Under the Government's fresh start package, from today those young people will no longer be dealt with by the Family Court.
The Youth Court will also have more powers.
Social Development Minister Paula Bennett said the court would be able to issue a range of compulsory orders, with longer interventions such as mentoring and drug and alcohol programmes along with tougher, more effective sentences.
"Vitally, we have given Youth Court judges the ability to impose greater interventions to deal with the root causes of offending," Ms Bennett said.
Youth Court Judges have the option of placing young offenders on nine different programmes from military-style activity camps to mentoring, parenting and alcohol and drug rehabilitation programmes.
Fresh Start will cost $84 million over the next three years.
Labour say the "boot camp" idea has been proven not to work and is a wrong use of resources.