HCC category assignment is most similar to DRG diagnostic category logic because both methods take detailed diagnosis coding and map it into clinically meaningful groupings used for payment or performance methodologies. In CMS-HCC risk adjustment, ICD-10-CM diagnosis codes map to Condition Categories (HCCs) that represent disease groups with expected cost and complexity, and the model applies rules such as hierarchies (to avoid double-counting related conditions) and, in some cases, interactions (to recognize added impact when certain conditions coexist). DRGs similarly group diagnoses (and procedures in the inpatient setting) into a limited number of categories intended to reflect resource consumption and clinical similarity, rather than paying strictly on every individual code. By contrast, 835 is a remittance advice transaction standard (payment explanation) and has nothing to do with clinical grouping methodology. ICD-10-PCS and CPT are procedure/service coding systems; they describe interventions performed, not the risk-category grouping of diagnoses. Therefore, DRG diagnostic categories are the closest conceptual match to HCC assignment methodology.