Last year, 14.3 per cent of the total population were 65 and over, compared to 12 per cent in 2002.
Other factors identified by Stats NZ include that people may be more willing to report their limitations, as public perception of disability changes.
Survey methods may also be improving to capture more cases.
In the 2013 survey, people aged over 65 were far more likely to be disabled (59 per cent) than adults under 65 (21 per cent) and children under 15 (11 per cent).
The most common disability was physical, except for children, for whom more than half - 53 per cent - had a learning disability.
The most common cause of child disabilities was a condition that existed at birth. For adults, it was disease or illness.
More than half of all disabled people - 53 per cent - had more than one disability.
Maori had an above average disability rate at 26 per cent, despite having a younger average age than the rest the population. In contrast, the disability rate for Pacific people was 19 per cent, below the average.
Taranaki had a disproportionate level of disabled people (30 per cent of the population), followed by Northland (29 per cent), and Bay of Plenty and Manawatu-Wanganui (both 27 per cent).
Auckland had 19 per cent.
Statistics NZ defines a disability as "an impairment that has a long-term, limiting effect on a person's ability to carry out day-to-day activities".
Long-term is defined as six months or longer.
