If Range("SupportUnrstrd")(i).Offset(0,-
21) < "500" _
Or Range("SupportUnrstrd")(i).Offset
(0, -21) < "550" Then

this will always return True. If the cell does equal 500, then the second
part will be True and

True Or False = True

You'll never have a False Or False result, so every cell will be processed.

--
Dick Kusleika
MVP - Excel
Excel Blog - Daily Dose of Excel
www.dicks-blog.com