The beds were previously run by University Hospitals of Northamptonshire before NHFT took over provision earlier this year.
In total, there are 19 beds for people experiencing spells of sudden confusion (delirium) and seven that can be used if demand increases.
Anne Rackham, NHFT’s chief operating officer, said: “Our community hospitals are a really important part of people’s recovery journeys, helping them to regain their health, independence and confidence after treatment in an acute hospital for illness or injury.
“I’d like to thank everyone behind the scenes who has worked so hard to complete the full opening of our community hospital service ahead of the winter, which is always a busy time for the NHS.”
The trust said people stay after being referred by a team of healthcare professionals who have carefully assessed their needs.
Staff at the centres include doctors, nurses, therapists and healthcare assistants, providing therapy and exercise to help patients “regain their strength, fitness and confidence to return home”, the trust added.