The legislation, which passed unanimously late on Tuesday, empowers a single doctor to approve an abortion up to 24 weeks.

Termination after 24 weeks gestation will require clinical advice from two doctors.

Previously, women required the consent of two doctors to terminate a pregnancy beyond 14 weeks.

Health Minister Natasha Fyles said one per cent of NT abortions happened after 20 weeks when a serious or lethal foetal anomaly was found.

"This highlights the incredibly small number of terminations that occur in the later stages, they are rare, complex situations," she said.

The amendments will benefit women in regional and remote communities who often travel hundreds, if not thousands, of kilometres for medical treatment.

Meanwhile, the age up to which support will be provided for vulnerable young people leaving out-of-home care in the territory has been extended from 18 years to 22.

The new legislation ensures children who were in foster care or child protection receive ongoing help until they are young adults, including financial assistance to maintain appropriate living standards.

It also improves inter-agency co-operation and information sharing to better protect children and young people while they are in the system.

The law aligns the NT with the ACT, Queensland, South Australia, Tasmania, Victoria and Western Australia, which have already committed to extending support.

"Supporting children, young people and families before reaching crisis is critical in improving outcomes," Minister for Territory Families and Urban Housing Kate Worden said.

Australian Associated Press