Lincolnshire County Council has decided to continue to run 17 day services and modernise the service for the future.
The council has been exploring the option of transferring the day services to Lincolnshire Partnership NHS Foundation Trust (LPFT).
Despite negotiation between the council and LPFT, the organisations did not reach an agreement.
Coun Mrs Patricia Bradwell, executive member for adult care, said: “The day services are very important and valued by the people who use them; our priority has been to secure a safe and sustainable service for those people.
“It is very disappointing we did not reach an agreement with LPFT which would adequately assure us that the remaining 17 services would be fit for the future.
“I would like to reassure people that day services remain unchanged and people who need to use this service can continue to do so.
“We will now continue to modernise the service ourselves, working with carers, service users and staff.”