Name the range, on the first sheet, containing the codes, say, ProcCodes

Assuming that the Procedure Codes in the second sheet are in column A, i.e., A2:An (adjust to suit)
Select A2:An

Home > Conditional Formatting > New Rule > Use a formula to determine which cell to format

enter this formula
=COUNTIF(ProcCodes,A2)
pick the format you want
Ok, Ok