SELECT	*
FROM	(
		SELECT	ROW_NUMBER() OVER ( PARTITION BY Client.ID, Patient.SSN ORDER BY StartOfCare ) AS RN,
			Client.ID, Client.ClientName, Patient.ClientID, Patient.SSN, Patient.StartOfCare, Patient.PrimDiag
		FROM	Client Client
		INNER JOIN Patient Patient ON Client.ID = Patient.ClientID
		WHERE	Patient.RptYear = 2012 AND Patient.PrimDiag <> 'NULL' AND Patient.PrimDiag <> '' AND Patient.SSN <> ''
	) P
WHERE	P.RN > 1