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Incorrect Medial Branch Block Reporting: Top Procedural Mistake Found During Pain Management Audits

CPT copyright 2009 American Medical Association. All rights reserved. CPT is a registered trademark of the American Medical Association.


Medial branch blocks can be easily over-reported if spinal anatomy is not understood or the actual procedure is not detailed. A procedural note stating, "medial branch blocks of L3, L4 and L5 nerves" followed by an insufficient description can be misleading and has ultimately proved disastrous in terms of inappropriate reporting.


According to the AMA, the code series for medial branch blocks and the facet joint injections are the same (i.e., CPT series 64490-64495), with reporting based on the number of facet joints injected, not the number of nerves injected. Because each lumbar facet joint is innervated by two medial branches of the primary dorsal ramus, both must be anesthetized to completely block a single joint. For example, to block the L4-L5 facet joint, both L3 and L4 medial branch nerves are anesthetized at the transverse processes of L4 and L5 respectively. CPT codes 64490-64495, according to the AMA CPT Assistant, "refer to the injection of a facet joint either by injection into the joint with one needle puncture or by anesthetizing the two medial branch nerves that supply each joint (two needle punctures)."


Let's go back to our example of a procedural note stating medial branch blocks of the L3, L4 and L5 nerves. The L3, L4 and L5 medial branch nerves innervate the L4-L5 and L5-S1 facet joint. We would report two CPT codes (64493 and 64494 provided the injections were performed with fluoroscopic guidance or CT guidance) for two facet joint injections despite having injected three nerves. Remember, the code description is for a facet joint injection. (Aug. 2010 AMA CPT Assistant)

Documentation tip: Many physicians are very detailed in their operative report (descriptions and titles) to include "medial branch blocks L3, L4 and L5 nerves "at L4-5 and L5-S1 facet joints" with reiteration found in the description of the operative report. The simple addition of "at L4-5 and L5-S1 facet joints" makes all the difference to the novice coder when backed up by a detailed description and will eliminate erroneous reporting.


To reiterate, according to the AMA, when reporting medial branch blocks, if a physician states he intends to inject three medial branch nerves and he injects the L3, L4 and L5 medial branch nerves, we would only report two facet joint injection codes despite three nerves being injected. Remember, two nerves anatomically innervate each facet joint. So, we only report two CPT codes, not three.


Cristina Bentin can be reached at Learn more about Coding Compliance Management.

The information provided should be utilized for educational purposes only. Facilities are ultimately responsible for verifying the reporting policies of individual commercial and MAC/FI carriers prior to claim submissions.

Read more practical guidance from Cristina Bentin:


- 10 Best Practices for Establishing Internal Coding Audits


- ICD-10 Implementation for ASCs: What You Must Do Now


- 3 Critical Mistakes Made When Reporting Modifier -59

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