ICD-10 (International Classification of Diseases, 10th Revision) is
the global standard for classifying diagnoses and inpatient
procedures. In the United States it splits into two related but
distinct systems: ICD-10-CM (Clinical Modification,
for diagnoses) and ICD-10-PCS (Procedure Coding
System, for inpatient procedures). Together they carry roughly
150,000 codes, updated annually.
Coding ICD-10 well requires reading the full clinical chart —
admission note, operative report, progress notes, discharge summary
— extracting every codable fact, picking the most specific code
from a tree with thousands of children, and then sequencing
Principal vs Secondary diagnoses per the ICD-10-CM Official
Guidelines. A human coder typically spends 15 to 30 minutes per
inpatient case and longer on high-acuity charts. That is the work
ICD-10 AI is designed to compress.