UnitedHealth Group, the nation’s largest healthcare conglomerate, has secretly paid nursing homes thousands in bonuses to help slash hospital transfers for ailing residents – part of a series of cost-cutting tactics that has saved the company millions, but at times risked residents’ health, a Guardian investigation has found.

Those secret bonuses have been paid out as part of a UnitedHealth program that stations the company’s own medical teams in nursing homes and pushes them to cut care expenses for residents covered by the insurance giant.

In several cases identified by the Guardian, nursing home residents who needed immediate hospital care under the program failed to receive it, after interventions from UnitedHealth staffers. At least one lived with permanent brain damage following his delayed transfer, according to a confidential nursing home incident log, recordings and photo evidence.