How do I pivot data (from long to wide), sum by ID, while merging duplicates in SQL

You need to “FEED” your pivot with only the required columns

Example

select * 
 from  ( Select ID
               ,City
               ,State
               ,Year
               ,Dollars
          From  YourTable
       ) src
 pivot (sum(Dollars) for year in ([2017], [2018], [2019])) pvt