How can I compare what is in sheet 1 and not in sheet 2 Context: would like any CPT codes not on

Agnieszka-

Please review the example file.  I have included a few different ways of going about the issue.  I think the option on the "Conditional Formatting Example" Worksheet may work better for your needs.

One method uses the match() function to identify if the value is found in one column or the other, while the other method uses native functionality of  "Remove Duplicates" in conjunction with conditional formatting that highlights the duplicates.