The impact of the Covid pandemic has resulted in "unprecedented" numbers of children chronically absent from school, the Department of Education (DE) has said.
It said the rate of absences was evident from figures it collected during the 2021-22 school year.
Chronic absence is classed as missing more than 10% of the year.
The children's commissioner in England is concerned some pupils never fully returned to school after lockdowns.
An investigation by Dame Rachel de Souza suggested persistent absence from school was at a rate in England almost twice as high as before the pandemic.
Previous reports from the Northern Ireland Commissioner for Children and Young People (NICCY) also said that the pandemic and restrictions had "a severe impact" on children and young people.
Most pupils in Northern Ireland were taught remotely out of school for months in 2020 and in early 2021.
The Department of Education is carrying out an equality screening on a new way for schools to record the attendance of pupils ahead of the 2022-23 school year.
The new method is voluntary for schools, but it introduces tiers for rates of pupil absences.
"Chronic" absence is defined as a pupil missing between 10% and 20% of school days.
"Severe chronic" absence is if a pupil misses over 20% of school.
"The impact of the pandemic is such that schools and Education Welfare Service (EWS) are seeing unprecedented numbers of children falling into chronic and severe chronic attendance categories," the DE equality screening said.
"The application of absence tiers by schools will help to reinforce the importance of regular attendance at school.
"It will provide a more detailed analysis of the number and percentage of pupils falling into each tier and what strategies are needed to support those pupils.
"The guidance reflects that there is a range of pupils/groups of pupils who may have specific issues in attending school, and details the range of support mechanisms available.
"Ultimately, if we see improvements in the proportion of pupils defined as having chronic or severe chronic absence, that will be a success."
In England, parents can face a £60 fixed penalty fine if their children are persistently absent from school.
That is not the case in Northern Ireland but parents can ultimately be taken to court if their child has a high level of absence from school.
Normally in Northern Ireland if a pupil's attendance at school drops below 85% of days over a period of time, this triggers follow-up action.
Initially this can involve a parental visit from an education welfare officer, and there is usually a long process before parents are prosecuted.