It has been confirmed that Fronheulog House will close.
The home has 16 residents with a maximum number of 25 beds.
The decision comes after private owners Hafal Crossroads, after working with the Council, were unable to find funding to carry out what were deemed as essential repairs.
Kirsty Williams, Welsh Liberal Democrat Assembly Member for Brecon and Radnorshire, said:
“This is disappointing news for the staff and for the residents.
“From the information I have seen the decision was avoidable, and at the very least the home could have been kept open for longer. In correspondence with the Minister for Social Services in the Welsh Government it was confirmed to me that the home met the environmental standards under the Care Standards Act (2000), and the closure was not mandated by the Care and Social Services Inspectorate for Wales.
“This timescale will inevitably put pressure on the process of making sure residents are transferred to new accommodation and it’s vital Hafal and the Council get that right.