Low-spending households continued to face higher inflation than top earners in the third quarter although superannuitants were hit by rising rates and insurance costs, Stats NZ said.
Overall costs for the lowest-expenditure household group were up 0.8 per cent in the September 2017 quarter, compared with the June quarter, the government statistician said.
Households in the highest earning group saw their cost of living lift 0.5 per cent, Stats NZ said.
Superannuitants, however, experienced the highest inflation of all household groups in the September quarter, driven by rising prices for rates, and insurance. Their overall costs rose 0.9 per cent, compared with a 0.6 per cent rise overall for households.
"Nearly nine out of ten superannuitants own their own home, so they bear the brunt of rising home-ownership costs," consumer prices manager Matthew Haigh said.
"In September, rises in local authority rates and home insurance had the greatest impact on this group."
On an annual basis, living costs for low-spending households rose 2.6 per cent while they were up 2.3 per cent for beneficiaries and 1.5 per cent for the highest-expenditure household group, Stats NZ said.
Poorer households experienced a greater impact from increased prices for rents, insurance, and cigarettes and tobacco.
In contrast, high-spending households experienced more benefit from decreased prices for telecommunications services, and audiovisual equipment, according to Stats NZ.
"Prices increased over the year for essential items like rents, food, and petrol, while they fell for some luxury items," Haigh said.
"Households with more discretionary income have received the most benefit from cheaper high-tech products," he added.
The agency began publishing the quarterly data in November last year to provide new insights into inflation experienced by 13 different groups including beneficiaries, Maori, pensioners and others based on their income and spending patterns.