The merger of two mental health trusts will not happen before May, a meeting on Wednesday is expected to hear.
Suffolk Mental Health NHS Trust's board is meeting to discuss the proposed merger with Norfolk and Waveney on Wednesday.
The Strategic Health Authority's full board is expected to study the business case for the merger in January.
The two mental health trusts hope the secretary of state for health will approve the merger in March.
The joint mental health service would cover the whole of Norfolk and Suffolk, including Waveney which straddles the border.
It will also include Thetford in Norfolk which is currently served by Suffolk's trust.
The joint trust will also provide substance misuse and learning disability services.