Current and former Kāinga Ora tenants owe a combined $18.6 million in overdue rent.
The total has been revealed in response to an Official Information Act (OIA) request.
The department has been taking significant numbers of tenants to the Tenancy Tribunal in recent months over rent arrears.
In one case last month, a woman who owed $14,331 in rent arrears to the start of September was told by the tribunal to pay it off at $50 a week until the debt was cleared.
Kāinga Ora said while 85 percent of tenants paid their rent on time every week and were up-to-date on payments, "a small number" fell behind.
"As at August 25, 2024, $18.6 million in rent debt was owed by approximately 8100 tenants. Around 82 percent of these tenants have achieve repayment arrangements in place - this means they are both paying their regular rent on time and are making additional, sustainable payments to reduce their rent debt."
Nick Maling, general manager national services, said when a tenancy ended because of rent debt, the amount was held on the books and could be repaid by the former tenant.
"After seven years, we write-off any remaining debt owed by the former tenant. We are unable to provide you with an exact figure of rent debt that is written-off, as we do not separate this out from other debt held by former tenants."
Earlier, Maling said the department had to strike a balance around rental debt.
"Many of our customers live on very low incomes and have little or no money in reserve, which means even small, unexpected life events can push them into debt that can be difficult to recover from.
"When a customer falls behind on their rent, we contact them early and work closely with them to develop a plan that will support them as they work through rent-related issues. About three-quarters of customers with rent debt are actively making payments to reduce their debt.
"When customers refuse to engage with us about their debt and continue to not pay their rent, we take action under the Residential Tenancies Act. This has led to us terminating the tenancies of 15 customers in the past financial year."