select * from
( SELECT [Year]
,[Type]
,[Category]
,[AnnualCost]
,[TimeStamp] as MaxTimeStamp
,row_number() over (partition by [Year], [Type], [Category] order by [TimeStamp] desc ) as rn
FROM [PromOneSite].[Budgeting].[MISBasePrice]
where Year = 2016
and category IN ('Leasing Office Desktop')
and TimeStamp IS Not Null
) tt
where tt.rn = 1
