The government has announced a $2.5 million plan to help teens who failed critical NCEA reading, writing and maths tests earlier this year.

Education Minister Erica Stanford said the money would provide teachers at about 160 schools with literacy and numeracy teaching training, as well as release time to hold small group sessions with their students.

She said about 10,000 students would benefit in the current school term and in term 1 next year.

The funding was targeted based on results from the May round of tests, in which just 46 percent of the 55,000 students who attempted the numeracy test passed.

In reading and writing, the pass rates were 59 and 56 percent.

The government's announcement followed teachers' and principals' warnings that some students were struggling with the online tests and the alternative - 20 credits in specific standards - was also proving difficult.

They warned that NCEA achievement rates would plummet because students must pass the corequisites before they could be granted any NCEA qualifications.

Stanford said there was a delicate balance to be struck with the corequisites.

"When you see young people who are struggling to get across the line the first thing is 'oh well I will just drop the standard' but that doesn't help anyone and it doesn't help those young people. This is a foundational literacy and numeracy assessment, I need to get them across the line," she said.

Teachers had been very vocal about "the issues with the literacy and numeracy corequisite", Stanford said.

"It's really important that ... young people who are struggling to get their literacy and numeracy corequisite have more targeted support.

"So, small group interventions from teachers who are well-versed in the literacy and numeracy corequisites, who can sit and work in a tailored situation with those students to help them get across the line."

Stanford said certain schools and parts of New Zealand needed particular help.

The shift to structured literacy and numeracy in primary schools would ensure future cohorts of students were better prepared for the corequisites but in the meantime the government wanted to help teenagers who would not benefit from that change, she said.

"Those are the kids that are at the moment working really hard, they're sitting the co-requisite two or three or four times to get across the line.

"Being able to pay for release time to have that small-group, tailored support intervention in place to hep them get across the line is going to be just one of many things that we'll be announcing."

Stanford said schools in the initiative had students in Years 9-11 and she expected some would extend the extra help to students in Years 12-13 who were running out of time to pass the corequisites before they finished secondary school.

Funding for the intervention might be extended if results from the May round of corequisite tests next year showed it had been effective and if there was still need for it.

In September, Stanford announced the alternative pathway would remain until the end of 2027, two years later than originally planned.

'Playing catch up'

Secondary Principals' Association president Vaughan Couillault told Morning Report teachers were playing "catch up" with students.

He said $2.5m might seem like a lot of money, but divided up among schools and students, it wouldn't go far.

There were a number of reasons students were behind in literacy and numeracy, Couillault said.

"They're starting from a place further back than historically we would be comfortable with."

And that went all the way back to students starting primary school, he said.

"All along the way there's people playing catch up."

Couillault said it was important to get the curriculum changes in place and then worry about measuring achievement against that.