The initiative will cost $337 million to run for 12 months, and will see 5500 casual teachers, retired teachers and student teachers hired as tutors in every public school, as well as some independent and Catholic schools, in NSW.

A spokesperson for the NSW Department of Education said the program would work by providing funding for schools to employ educator "who will deliver small-group learning for students who need it most".

The schools that require the most attention will be determined by the standardised results of the 2020 check-in test which was rolled out for years 3, 5, and 9 in July.

The check-in took the place of the NAPLAN this year after COVID-19 forced its cancellation.

Up to three-quarters of the state's public schools took part in the optional examination.

It is an initiative that has been applauded by the NSW Teachers Federation.

But Riverina organiser of the federation, John Pratt shared concerns that the undertaking would be so huge, it would lead to some schools falling through the cracks.

"It remains to be seen how it will all be worked out," Mr Pratt said.

When schools across the state were locked down and home-learning became the norm in April, Mr Pratt said the federation suggested additional tutors be deployed.

"We would have liked to see it be done back then," he said.

"But the government has come around to seeing that this is a necessary thing to keep students from falling behind after this year."