The .sqlplan files for the queries that I put in the first message are attached.

MainDocumentAndAddendaActualPlan.sqlplan is from the first query

MainDocumentAndDiagnosesActualPlan.sqlplan is from the second query

MainDocumentAddendaAndDiagnosesEstimatedPlan.sqlplan is from the third query

MainDocumentAndAddendaIntoTempTableActualPlan.sqlplan is from saving the first query results in a temp table

MainDocumentAndDiagnosesIntoTempTableActualPlan.sqlplan is from saving the second query results in a temp table

MainDocumentAddendaAndDiagnosesFromTempTablesActualPlan.sqlplan is like the third query, but it uses the temp tables. That query looks like this:

SELECT doc_ad.TIUDocumentSID, doc_ad.ScrSSN, doc_ad.TIUDocumentSID, doc_dx.ICDCode

FROM #DocAndAdID AS doc_ad

LEFT JOIN #DocAndDxID AS doc_dx

ON doc_ad.TIUDocumentSID = doc_dx.TIUDocumentSID

ORDER BY doc_ad.TIUDocumentSID, doc_ad.TIUAddendumSID