Wide-ranging benefit reforms have come into force today, with beneficiary advocates voicing a mix of cautious optimism and criticism of the changes.

From today there are fewer benefit categories, as well as compulsory drug testing for jobseekers, sanctions for fugitive beneficiaries and stricter healthcare obligations for parents of young children.

A new way of dealing with hardcore beneficiaries will also be introduced, with the Government trumpeting the success of a pilot trialled in 24 Work and Income offices since October.

Work and Income says the results are "some of the best from any case management trial" in recent years, with 6000 of the 10,000 people in the pilot no longer on a benefit. More than half of those people found work, the rest opted out or cancelled benefits for reasons such as no longer meeting eligibility requirements.

From today, 91,000 people will be enrolled.

Social Welfare minister Paula Bennett said the changes focus on work and individuals, especially those at risk of long-term welfare dependence.

"People do have to turn up, they do have to be actively looking for work. But then equally they get the right level of support so they can do that and we're seeing great results for it," she said.

The ministry also has a pilot planned in the next two months to get 2000 sickness beneficiaries with mental and physical disabilities into work, she said.

The Government estimates 28,000 to 44,000 people will come off benefits by 2017 because of the reforms, saving up to $1.6 billion.

Some beneficiary advocates said the changes provided more certainty for those relying on welfare.

‘We always think of Winz as beating people with a stick but from what we see they're prepared to work with the advocates and work with the clients and . . . try and get them in a state when they can get into work," Porirua's Agape Budgeting Services manager Brian McGettigan said.

Sarah Thompson, of Auckland Action Against Poverty, said the reforms were about "cutting costs by pushing vulnerable people off the books" at a time when few jobs were available.

Labour social welfare spokeswoman Jacinda Ardern said she was hearing of solo mothers being forced to give up study for menial jobs allocated by Work and Income, such as washing dishes.

THE CHANGES

The number of benefits has been cut from seven main ones to three:

Jobseeker Support for those seeking and available for work, Sole Parent Support for sole parents with children under 14, and Supported Living Payment for people significantly restricted by sickness, injury or disability.

Beneficiaries must tell Work and Income if they plan to enrol children with a GP, a preschool from age 3, or a school from age 5.

They must also ensure health checks are up to date and notify Work and Income if they plan to leave the country.

They must undergo a drug test when required if they are on the Jobseeker benefit and turn themselves in if they have a warrant out for their arrest.