How close as a general rule do the different payers follow the CPT guidelines? Can the guidelines be interpreted one way by one carrier and a different way by another payer which would affect the way codes might be submitted for reimbursement? I've found this to be true in the application of modifiers depending on payer preferences. Makes it a real tricky process when fashioning appeals because it all involves "interpretation". And then there's the issue of understanding the particular carrier's edit system. What's the best approach to get a grasp of all this from the billing standpoint?