[dba-SQLServer] IN() or NOT IN()

I am trying to process a query where an income field has a set of possible
values, 1-9 and A-T.  The client wants values 409 and A-M.  Logically that
would be more efficient if it was NOT in(1-3,n-t).  Is it in fact more
efficient?  And can ranges like that be specified or do I need to use comma
delimted lists 1,2,3,n,o,p...?

John W. Colby
Colby Consulting
www.ColbyConsulting.com