AI correctly identified 90% of surgery billing codes in 1000 orthopaedic operative notes
Study title: Artificial Intelligence Accurately Assists in Billing for Orthopaedic Lower Extremity Surgery: Performance of the Mistral-NeMo Language Model
A peer-reviewed study tested the Mistral-NeMo language model on 1000 operative notes from 177 providers to verify Current Procedural Terminology codes for lower-extremity orthopaedic surgery. When CPT billing descriptions were included in the prompt, the model correctly identified 90% of true codes and rejected 99.80% of incorrect codes.
Read the study abstract
Purpose To elucidate Mistral-NeMo's proficiency as a novel artificial intelligence assistant to verify coding accuracy and improve efficiency in manual medical coding practices in orthopaedic surgery. Methods This study tested Mistral-NeMo on 1000 operative notes labeled with the Current Procedural Terminology (CPT) codes from 177 providers. In total, there were 46 unique CPT codes; the most common were 29881 (knee arthroscopy with meniscectomy for both medial and lateral menisci), 29880 (knee arthroscopy with m…

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G 56The G score combines the specificity and measured human impact of the grounded gain claim with the strength of this Trace’s cited sources.In brief
Automated validation could reduce incidental coding errors and administrative load that diverts clinicians and staff from patient care, but the reported high accuracy was observed only with descriptions provided. The study's scope was limited to femur- and knee-related notes and 46 codes, leaving open how the model would perform on broader procedures or without contextual descriptions.
Main points
- Study tested Mistral-NeMo on 1000 operative notes labeled with CPT codes from 177 providers covering 46 unique CPT codes.
- Most common codes were 29881, 29880, and 29888 for knee arthroscopy meniscectomy and ACL repair.
- Binary Yes/No trials and confidence score 0-100 trials used true codes and randomly selected incorrect codes as controls.
The gain
Mistral-NeMo verified orthopaedic lower-extremity billing by correctly identifying 90% of true CPT codes and rejecting 99.8% of incorrect codes when provided with billing descriptions.
The problem
Mistral-NeMo's high CPT-code accuracy was observed only when billing descriptions were included in the prompt, leaving performance without them untested.
The rundown
Researchers prompted Mistral-NeMo with 1000 operative notes from 177 providers, each paired with either the true CPT code or a randomly selected incorrect code as positive or negative controls.
The dataset included 46 unique CPT codes, with knee arthroscopy codes 29881, 29880, and 29888 most frequent, and prompts requested binary Yes/No or 0-100 confidence responses.
What this doesn’t fix
Performance depended on contextual information and was insignificant without billing descriptions, limiting use on operative notes alone.
Sources
- Peer-reviewedArthroscopy2026-09-06
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The debate