The government's new fees-free tertiary education policy will see taxpayers footing the bill for people studying golf and homeopathy, the National Party says.

Education Minister Chris Hipkins on Tuesday confirmed any New Zealander who has done less than half a year of full-time study will get a free full-time year of tertiary education from 2018.

About 80,000 people are expected to be eligible - including those graduating high school in 2017 - with 50,000 to train in polytechnics or industry courses and 30,000 at universities.

Hipkins said the policy had already been budgeted for, along with the government's $50-a-week increase to student allowances, at a cost of about $380 million.

READ MORE: 80,000 people expected to get fee-free study in 2018

But National's tertiary education spokesman, Paul Goldsmith, called the scheme "expensive and untargeted" and said it would just see people studying "golf, homeopathy and skydiving" for free.

"They might decide later in life that it's time to do a bit of training on the golf swing and this is something you'll be able to get free," he told reporters.

Goldsmith said figures given to cabinet also showed very few additional people would be encouraged into study by the policy, and most who would take it up next year were already enrolled anyway.

"Instead of trying to get the students ... who wouldn't have gone otherwise, they're paying for everybody," he said.

The government expects the overall number of students enrolling to grow by about 3 per cent - or 2000 students - from next year because of the scheme.

Meanwhile, the Union of Students' Associations welcomed the fact the policy also covered compulsory student services fees and allowed people to take the free year part-time over 24 months.

"This gives real options for prospective students, and will hopefully level the playing field between trades training and university," union national president Jonathan Gee said.

The Tertiary Education Commission has been given the responsibility of implementing the policy.

It's set up a website to help prospective students check if they qualify and would be working with tertiary organisations to minimise the extra amount of work they would needed to do, Hipkins said.

"I appreciate that enrolled and prospective learners have had to wait some time before seeing the final details of the fees-free policy," he said.

But Goldsmith said the sector had been "left in the dark for months" and now had less than a month to prepare.

The government has previously promised the policy would be rolled out to cover three years of education by 2024.