The county's primary care trust has agreed to consider an option keeping accident and emergency, intensive care, routine elective surgery and acute medicine at Chichester, Worthing and Haywards Heath.
However, this would also involve a staged centralisation of consultant-led maternity services, inpatient children's services and most trauma and emergency surgery at either Worthing or Chichester.
Brighton and Sussex University Hospitals trust - which runs the Princess Royal Hospital at Haywards Heath - has already proposed keeping A&E and acute medical services there.
The PCT will now look at the three-A&E model, which was backed by senior clinicians alongside two other models. A decision on which of the three options to adopt is expected in May, but the precise location of services will only be decided in June.
The move is a culmination of a bitter two-year battle over the county's services, which has seen politicians, media and many members of the public oppose the PCT's original proposals - which would have meant two out of the three hospitals losing significant parts of their acute services, including A&E.
Last October Rolling Stone Keith Richards headed one of many protest marches in the county.