Social workers will have to be registered under a proposed new law designed to put them under greater scrutiny.
The government will introduce legislation to Parliament in August that will make the change, including new performance standards and ongoing professional development.
It is also hiring an extra 42 social workers to work for the Ministry for Vulnerable Children, Oranga Tamariki.
Last year a select committee inquiry recommended making registration mandatory, after fears were raised that thousands of people were working with some of the country's most vulnerable children, without any oversight, qualifications or police clearance.
A register has been in place since 2003, but it is on a voluntary basis.
About 6300 social workers are registered.
At the last census as many as 18,000 people identified themselves as practising as a social worker.
Social Development Minister Anne Tolley said it was time all social workers met the same type of standards as other skilled professions.
"It's intensely significant work that they do in our communities ... to give them that mana so they can sit at the table alongside other qualified professionals like teachers and nurses, is crucially important."
The new law would restrict the use of the term social worker to those who have proved they have the required qualifications, skills and experience.
There would also be changes to simplify the current registration process.
Ms Tolley said the cost of registration under the new regime was expected to be lower than the current initial fee of about $1000.
She said all social workers would be subject to a complaints and disciplinary process.
"If you get de-registered then you cannot call yourself a social worker ... and go and get yourself another job."
Chief executive of the Social Workers registration board Sarah Clark backed the move.
"Having consistent standards across the country means the drive behind lifting practise and lifting the standing of the profession is something that all social workers will buy into."
Labour Party social development spokesperson Carmel Sepuloni said mandatory registration had been a long time coming - and her only concern the cost.