Wiki SNF admission Principle diagnosis

[creehle]

At a seminar we were informed that the principle diagnosis for a Medicare A admission to the SNF is the diagnosis that the resident had prior to the admission to a hospital ( ex Parkinsons). Wouldn't the principle diagnosis be the primary reason that the resident is receiving skilled care post hospitalization? (ex: Pneumonia, fracture, etc) Can you refer me to where these specific directions would be for choosing the Principle diagnosis?