OLYMPIA – Washington state Attorney General Bob Ferguson has joined with the U.S. Department of Justice and eight state attorneys general to file a lawsuit accusing RealPage, a nationwide revenue management software company, of colluding with landlords to raise rent prices.

According to a press release, RealPage is the leading revenue management software system for U.S. landlords. The software has been used to price approximately 800,000 leases in Washington over the past seven years.

In January 2023, Ferguson launched an investigation into RealPage after an article by ProPublica, a nonprofit media organization in New York, detailed how RealPage’s algorithm could contribute to rising rents across the country.

According to a Washington Post analysis of rental data, rents have increased 41% in Chelan County and 22.8% in Douglas County since 2019, while rents nationwide have increased only 19% over the same period.

Ferguson’s investigation found that RealPage collected private, sensitive data from landlords and used it to make rental price recommendations, according to a press release.

The lawsuit, filed Friday, accuses RealPage of feeding its algorithm with private data and advising landlords to maintain or increase their rent prices even when occupancy is low.

“RealPage has conspired to manipulate prices and keep rents rising to increase profits,” Ferguson said in a press release. “Housing costs are a burden on too many working families. My team and I will oppose these arrangements and fight for affordable rents in Washington.”