Medical coding itself is a difficult task. Beyond that, surgical coding is difficult since it is a task to be held with responsibility. Most of the medical coders struggle with coding operative reports because there are too many guidelines and policies that affect code selection. The process becomes easier when you break it down into seven steps. Step by step processes always win due to the unique way of handling them.

As the coding guidelines and coding concepts keep on changing, it becomes even more stringent for healthcare professionals to run behind accuracy. Surgical coding remains different from other coding procedures, as it holds on to accuracy completely. Of course, it’s very important to code accurately so that they don’t miss out their payments from the payers.

In this article, we shall learn about the seven steps for accurate surgical coding. The steps are:

7 steps for accurate surgical coding:

  1. Review the header of the report
  2. Review the CPT code book
  3. Review the documentation
  4. Make preliminary code selection
  5. Review the guidelines for preliminary codes
  6. Review policies and eliminate the extras
  7. Add any needed modifiers


1. Review the header of the report:

  • It entirely depends on what the healthcare professional said was performed and why?
  • PREOPERATIVE DIAGNOSIS: Left medial compartment osteoarthritis of the knee.
    POSTOPERATIVE DIAGNOSIS: Left medial compartment osteoarthritis of the knee.
    PROCEDURE PERFORMED: Left unicompartmental knee replacement.
    Based on the documentation above, a unicompartmental knee replacement on the left knee was performed. A unicompartmental knee replacement indicates only one of the three compartments of the knee (medial, lateral, or patellofemoral) was altered during the procedure. The postoperative diagnosis field indicates the altered compartment was the medial compartment of the left knee. Verification of the statement will take place later.

2. Review the CPT code book:

  • Based on the header report from the report, it’s essential to review the CPT code book in order to identify various coding options.
  • Healthcare professional must also verify and identify the differences between the codes and the documentation required to support one service over another.
  • Continuing with the example given, the Index is reviewed first to identify all possible code options for knee replacement procedures.
  • Replacement – Knee


Intra-operative Use, Kinetic Balance


Partial and


  • Three options are given: Intra-operative use of kinetic balance sensor for implant stability during knee replacement arthroplasty (List separately in addition to code for primary procedure), Arthroplasty, knee, condyle and plateau; medial OR lateral compartment, and Arthroplasty, knee, condyle and plateau; medial AND lateral compartments with or without patella resurfacing (total knee arthroplasty).
  • Upon reviewing the three options, a particular code is found to be an add-on code. So neither can it be reported alone, nor be the first-listed CPT code reported. But it does indicate that a specific technology was used during the procedure. If that technology is included in the full report (which will be reviewed in Step 3), reviewed code will be included in Step 4.
  • Surgical coding CPT codes differ based on one key word: “OR” vs. “AND”. Code indicates a partial knee replacement – including either the medial OR the lateral compartment was performed, while it can also indicates a total knee replacement-including both the medial AND lateral compartments was performed. When the documentation is reviewed fully, the primary focus will be to determine which compartments were altered during the procedure.

3. Review the documentation:

  • Based on the surgical coding documentation, a unicompartmental knee replacement using a Biomet, including prosthesis was performed. The components were cemented into the tibia and distal femur after the necessary cuts and trial fit/placement were performed. According to the Cleveland Clinic, “Medial knee joint degeneration is the most common deformity of arthritis.”

4. Make preliminary code selection:

  • The emphasis here is to make a preliminary code selection based on the documentation. It’s preliminary because reviewing the guidelines, policies, etc., may lead to eliminating certain codes, or the need for additional codes and/or modifiers.
  • Based on the surgical coding documentation above, a unicompartmental knee replacement is supported. A unicompartmental knee replacement is also referred to as a “partial” knee replacement. So based on the code options, surgical coding CPT code is supported, preliminary. Guidelines and policies still need to be reviewed.
  • If surgical coding is performed for a facility, the implant also requires to be reported.

5. Review the guidelines for preliminary codes:

  • Review all the relevant CPT coding guidelines, including parenthetical references, to ensure all rules are followed and additional, supported services are captured. Steps 5, 6, and 7 are all related, and are frequently performed concurrently.
    The “Femur (Thigh Region) and Knee Joint/ Repair, Revision, or Reconstruction” CPT codes do not include specific subsection guidelines. But there are two parenthetical references codes to review, and the general surgery guidelines (at the beginning of the Surgery section of CPT) still apply.
    The parenthetical references under:
  • Codes for revision of total knee arthroplasty, and codes for the removal of total knee prosthesis:
    Both parenthetical references are specific to total knee arthroplasties, particularly revision or removal of previously placed prosthesis, and are not relevant.
  • Based on the surgical coding documentation for this scenario, a partial knee arthroplasty was performed in a knee without a previous prosthesis or implant. No additional CPT guidelines appear to be relevant for this scenario.

6. Review policies and eliminate the extras:

  • Just because there is only one service supported based on the documentation and steps above, it appears there are no extras. Review all of the relevant edits and policies (National Correct Coding Initiative (NCCI) edits, local and national coverage determinations (LCDs, NCDs), payer contracts, medical policies, etc.) to ensure bundled services are appropriately eliminated and tracked internally, if applicable.
  • This step is essential in scenarios where more than one service is performed and more than one code may be warranted. Reviewing the NCCI edits and payer policies will help you identify bundled services, instances where modifiers may be needed, or situations where a contract limitation restricts reporting a service that would otherwise be reportable.

7. Add any needed modifiers:

  • Based on the description, there is no indication as to which knee was repaired. The story is incomplete. A modifier is needed to indicate which knee was affected.
  • Modifier options are:
    LT left side
    RT right side
    50 bilateral procedure
  • Based on the surgical coding documentation, the left knee was replaced because the patient had a right-side replacement previously. For this situation, modifier LT is added to the procedure to indicate the procedure was performed on the left knee. Without this modifier, a denial or request for additional information may be received from the payer because the patient had the previous knee replacement.


Modifiers are very essential while coding any procedures. Without modifiers, the codes will not be explained clearly. Moreover, insurance companies will need complete documentation with accurate modifiers attached to the codes.


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