Posterior instrumentation for spinal fusion

July 25, 2022 / By Rhonda Talley

Posterior instrumentation is commonly performed with posterior and/or anterior column fusion procedures. For CPT® reporting, it is appropriate to assign codes for posterior instrumentation in conjunction with spinal arthrodesis codes. Deciding which posterior instrumentation code to report can cause some confusion.   

For correct code selection, look for documentation of the sites where instrumentation is attached to the posterior spine.  

First, let’s look at two examples of posterior instrumentation. 

Example 1: Patient A has a posterior column fusion at L2-L5 with autograft and pedicle screw fixation. The provider specifies that the pedicle screws are inserted into the pedicles at L2-L3, L3-L4 and L4-L5 bilaterally. In this case, the documentation clearly indicates that the construct of screws and rods spans four vertebral segments and is fixated at each end with bony attachment in between. In this case, add-on code 22842 is appropriate for segmental instrumentation.    

The codes in range 22842-22844 indicate posterior segmental instrumentation and are broken down by the number of vertebral segments that the instrumentation construct spans.   

Diagram of segmental spinal instrumentation with fixation at each end of construct with at least one bony attachment in between  

Example 2:  Now let’s look at Patient B who also has posterior spinal fusion from L2-L5. In this case, the provider places the pedicle screws at L2 and L5. The construct of screws and rods spans four vertebral segments but is only fixated at L2 and L5, with no bony attachment in between. This is reported with add-on code 22840 for non-segmental instrumentation.  

Non-segmental spinal instrumentation with fixation at each end of construct with no bony attachment in between

*CPT Assistant®, July 2013 pages 3-5 entitled “Spinal Instrumentation” provides an illustration of non-segmental posterior column fixation spanning multiple vertebral segments with attachment at the proximal and distal sites with no bony attachments in between.   

Additional information and examples for posterior spinal instrumentation are found in *CPT Assistant, February 1996 pages 7-8 entitled “Spinal instrumentation, posterior.”  

One final note – always check the parenthetical notes following the add-on codes to make sure that the appropriate base code is also being reported. 

Stay tuned for my next blog on anterior instrumentation for spinal fusion! 


Rhonda, CCS, CPC, is a senior nosology analyst with 3M Health Information Systems. 

The information in the article is appropriate for use in facility and physician coding. 

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