How to Use the KX Modifier for ASC Pain Management Diagnostic Blocks
When billing pain management diagnostic blocks in an ASC, it is often appropriate to use the KX modifier. Such usage applies to Medicare and those commercial payers that may follow Medicare guidelines and local coverage determination (LCD) rules.
The purpose of reporting the KX modifier for diagnostic injections is to avoid frequency denials since diagnostic injections are billed using the same CPT codes as treatment injections to manage pain. Diagnostic injections are not counted towards the frequency requirements. For example, no more than four epidural injection sessions may be reported per region in a rolling 12-month period.
Both the diagnostic block and epidural injection are billed with the same CPT codes. It is typical for patients to receive up to two diagnostic blocks in a single procedure. If more are performed, the case may be flagged for an audit.
To learn more about reporting the KX modifier for diagnostic purposes in an ASC, access these Medicare local coverage articles for various pain management injections: