Yes, DB2 has the MERGE statement, which will do an UPSERT (update or insert).
MERGE INTO target_table USING source_table ON match-condition
{WHEN [NOT] MATCHED
THEN [UPDATE SET ...|DELETE|INSERT VALUES ....|SIGNAL ...]}
[ELSE IGNORE]
See:
https://www.ibm.com/developerworks/community/blogs/SQLTips4DB2LUW/entry/merge?lang=en