What the two CMS-HCC mappings do differently, code by code.
Both models on the FY2025 code set, payment year 2025 — the last year CMS published V24 and V28 together. Comparing across different years would mix a model change with a code-set change and call the result a model change.
A code that maps in one model and not the other is a statement about the model, not about the documentation. The note in the chart is unchanged either way, and so is what it supports.
These carried a category under V24 and carry none under V28.
| Code | Description | V24 | V28 |
|---|---|---|---|
| A01.03 | Typhoid pneumonia | HCC115 | — |
| A02.22 | Salmonella pneumonia | HCC115 | — |
| A20.2 | Pneumonic plague | HCC115 | — |
| A21.2 | Pulmonary tularemia | HCC115 | — |
| A22.1 | Pulmonary anthrax | HCC115 | — |
| A39.1 | Waterhouse-Friderichsen syndrome | HCC23 | — |
| A42.0 | Pulmonary actinomycosis | HCC115 | — |
| A43.0 | Pulmonary nocardiosis | HCC115 | — |
| A54.84 | Gonococcal pneumonia | HCC115 | — |
| B38.0 | Acute pulmonary coccidioidomycosis | HCC115 | — |
| B38.1 | Chronic pulmonary coccidioidomycosis | HCC115 | — |
| B38.2 | Pulmonary coccidioidomycosis, unspecified | HCC115 | — |
| B39.0 | Acute pulmonary histoplasmosis capsulati | HCC115 | — |
| B39.1 | Chronic pulmonary histoplasmosis capsulati | HCC115 | — |
| B39.2 | Pulmonary histoplasmosis capsulati, unspecified | HCC115 | — |
| B40.0 | Acute pulmonary blastomycosis | HCC115 | — |
| B40.1 | Chronic pulmonary blastomycosis | HCC115 | — |
| B40.2 | Pulmonary blastomycosis, unspecified | HCC115 | — |
| B41.0 | Pulmonary paracoccidioidomycosis | HCC115 | — |
| B66.4 | Paragonimiasis | HCC115 | — |
| B67.1 | Echinococcus granulosus infection of lung | HCC115 | — |
| D55.0 | Anemia due to glucose-6-phosphate dehydrogenase deficiency | HCC48 | — |
| D55.1 | Anemia due to other disorders of glutathione metabolism | HCC48 | — |
| D55.21 | Anemia due to pyruvate kinase deficiency | HCC48 | — |
| D55.29 | Anemia due to other disorders of glycolytic enzymes | HCC48 | — |
| D55.3 | Anemia due to disorders of nucleotide metabolism | HCC48 | — |
| D55.8 | Other anemias due to enzyme disorders | HCC48 | — |
| D55.9 | Anemia due to enzyme disorder, unspecified | HCC48 | — |
| D56.0 | Alpha thalassemia | HCC48 | — |
| D56.4 | Hereditary persistence of fetal hemoglobin [HPFH] | HCC48 | — |
| D56.8 | Other thalassemias | HCC48 | — |
| D57.3 | Sickle-cell trait | HCC48 | — |
| D58.0 | Hereditary spherocytosis | HCC48 | — |
| D58.1 | Hereditary elliptocytosis | HCC48 | — |
| D58.2 | Other hemoglobinopathies | HCC48 | — |
| D58.8 | Other specified hereditary hemolytic anemias | HCC48 | — |
| D58.9 | Hereditary hemolytic anemia, unspecified | HCC48 | — |
| D59.0 | Drug-induced autoimmune hemolytic anemia | HCC46 | — |
| D59.2 | Drug-induced nonautoimmune hemolytic anemia | HCC46 | — |
| D60.1 | Transient acquired pure red cell aplasia | HCC46 | — |
| D61.1 | Drug-induced aplastic anemia | HCC46 | — |
| D61.810 | Antineoplastic chemotherapy induced pancytopenia | HCC47 | — |
| D61.811 | Other drug-induced pancytopenia | HCC47 | — |
| D61.9 | Aplastic anemia, unspecified | HCC46 | — |
| D64.2 | Secondary sideroblastic anemia due to drugs and toxins | HCC48 | — |
| D65 | Disseminated intravascular coagulation | HCC48 | — |
| D68.312 | Antiphospholipid antibody with hemorrhagic disorder | HCC48 | — |
| D68.318 | Oth hemorrhagic disord d/t intrns circ anticoag,antib,inhib | HCC48 | — |
| D68.32 | Hemorrhagic disord d/t extrinsic circulating anticoagulants | HCC48 | — |
| D68.4 | Acquired coagulation factor deficiency | HCC48 | — |
| D68.51 | Activated protein C resistance | HCC48 | — |
| D68.52 | Prothrombin gene mutation | HCC48 | — |
| D68.59 | Other primary thrombophilia | HCC48 | — |
| D68.61 | Antiphospholipid syndrome | HCC48 | — |
| D68.62 | Lupus anticoagulant syndrome | HCC48 | — |
| D68.69 | Other thrombophilia | HCC48 | — |
| D68.8 | Other specified coagulation defects | HCC48 | — |
| D68.9 | Coagulation defect, unspecified | HCC48 | — |
| D69.0 | Allergic purpura | HCC48 | — |
| D69.2 | Other nonthrombocytopenic purpura | HCC48 | — |
Showing the first 60 of 2,252, in code order. Every code page carries its own mapping in every loaded model.
Almost every mapped code is in this list, and that is a fact about the numbering rather than about the code. V28 renumbered its categories wholesale, so a different number on its own does not mean the code was reclassified — read the two categories, not the fact that they differ.
| Code | Description | V24 | V28 |
|---|---|---|---|
| A01.04 | Typhoid arthritis | HCC39 | HCC92 |
| A01.05 | Typhoid osteomyelitis | HCC39 | HCC92 |
| A02.23 | Salmonella arthritis | HCC39 | HCC92 |
| A02.24 | Salmonella osteomyelitis | HCC39 | HCC92 |
| A06.5 | Amebic lung abscess | HCC115 | HCC283 |
| A36.81 | Diphtheritic cardiomyopathy | HCC85 | HCC227 |
| A39.83 | Meningococcal arthritis | HCC39 | HCC92 |
| A39.84 | Postmeningococcal arthritis | HCC39 | HCC92 |
| A48.0 | Gas gangrene | HCC106 | HCC263 |
| A48.1 | Legionnaires' disease | HCC114 | HCC282 |
| A50.55 | Late congenital syphilitic arthropathy | HCC39 | HCC92 |
| A54.40 | Gonococcal infection of musculoskeletal system, unspecified | HCC39 | HCC92 |
| A54.41 | Gonococcal spondylopathy | HCC39 | HCC92 |
| A54.42 | Gonococcal arthritis | HCC39 | HCC92 |
| A54.43 | Gonococcal osteomyelitis | HCC39 | HCC92 |
| A54.49 | Gonococcal infection of other musculoskeletal tissue | HCC39 | HCC92 |
| A54.85 | Gonococcal peritonitis | HCC33 | HCC78 |
| A66.6 | Bone and joint lesions of yaws | HCC39 | HCC92 |
| A69.23 | Arthritis due to Lyme disease | HCC39 | HCC92 |
| A81.00 | Creutzfeldt-Jakob disease, unspecified | HCC52 | HCC127 |
| A81.01 | Variant Creutzfeldt-Jakob disease | HCC52 | HCC127 |
| A81.09 | Other Creutzfeldt-Jakob disease | HCC52 | HCC127 |
| A81.1 | Subacute sclerosing panencephalitis | HCC52 | HCC127 |
| A81.2 | Progressive multifocal leukoencephalopathy | HCC52 | HCC127 |
| A81.81 | Kuru | HCC52 | HCC127 |
| A81.82 | Gerstmann-Straussler-Scheinker syndrome | HCC52 | HCC127 |
| A81.83 | Fatal familial insomnia | HCC52 | HCC127 |
| A81.89 | Other atypical virus infections of central nervous system | HCC52 | HCC127 |
| A81.9 | Atypical virus infection of central nervous system, unsp | HCC52 | HCC127 |
| B00.82 | Herpes simplex myelitis | HCC72 | HCC182 |
| B01.12 | Varicella myelitis | HCC72 | HCC182 |
| B02.24 | Postherpetic myelitis | HCC72 | HCC182 |
| B06.82 | Rubella arthritis | HCC39 | HCC92 |
| B18.0 | Chronic viral hepatitis B with delta-agent | HCC29 | HCC65 |
| B18.1 | Chronic viral hepatitis B without delta-agent | HCC29 | HCC65 |
| B18.2 | Chronic viral hepatitis C | HCC29 | HCC65 |
| B18.8 | Other chronic viral hepatitis | HCC29 | HCC65 |
| B18.9 | Chronic viral hepatitis, unspecified | HCC29 | HCC65 |
| B26.85 | Mumps arthritis | HCC39 | HCC92 |
| B33.24 | Viral cardiomyopathy | HCC85 | HCC227 |
| B42.82 | Sporotrichosis arthritis | HCC39 | HCC92 |
| B44.81 | Allergic bronchopulmonary aspergillosis | HCC112 | HCC280 |
| C01 | Malignant neoplasm of base of tongue | HCC11 | HCC21 |
| C02.0 | Malignant neoplasm of dorsal surface of tongue | HCC11 | HCC21 |
| C02.1 | Malignant neoplasm of border of tongue | HCC11 | HCC21 |
| C02.2 | Malignant neoplasm of ventral surface of tongue | HCC11 | HCC21 |
| C02.3 | Malig neoplasm of anterior two-thirds of tongue, part unsp | HCC11 | HCC21 |
| C02.4 | Malignant neoplasm of lingual tonsil | HCC11 | HCC21 |
| C02.8 | Malignant neoplasm of overlapping sites of tongue | HCC11 | HCC21 |
| C02.9 | Malignant neoplasm of tongue, unspecified | HCC11 | HCC21 |
| C03.0 | Malignant neoplasm of upper gum | HCC11 | HCC21 |
| C03.1 | Malignant neoplasm of lower gum | HCC11 | HCC21 |
| C03.9 | Malignant neoplasm of gum, unspecified | HCC11 | HCC21 |
| C04.0 | Malignant neoplasm of anterior floor of mouth | HCC11 | HCC21 |
| C04.1 | Malignant neoplasm of lateral floor of mouth | HCC11 | HCC21 |
| C04.8 | Malignant neoplasm of overlapping sites of floor of mouth | HCC11 | HCC21 |
| C04.9 | Malignant neoplasm of floor of mouth, unspecified | HCC11 | HCC21 |
| C05.0 | Malignant neoplasm of hard palate | HCC11 | HCC21 |
| C05.1 | Malignant neoplasm of soft palate | HCC11 | HCC21 |
| C05.2 | Malignant neoplasm of uvula | HCC11 | HCC21 |
Showing the first 60 of 7,585, in code order. Every code page carries its own mapping in every loaded model.
New to the model — these carried no category under V24.
| Code | Description | V24 | V28 |
|---|---|---|---|
| D3A.00 | Benign carcinoid tumor of unspecified site | — | HCC22 |
| D3A.010 | Benign carcinoid tumor of the duodenum | — | HCC22 |
| D3A.011 | Benign carcinoid tumor of the jejunum | — | HCC22 |
| D3A.012 | Benign carcinoid tumor of the ileum | — | HCC22 |
| D3A.019 | Benign carcinoid tumor of the small intestine, unsp portion | — | HCC22 |
| D3A.020 | Benign carcinoid tumor of the appendix | — | HCC22 |
| D3A.021 | Benign carcinoid tumor of the cecum | — | HCC22 |
| D3A.022 | Benign carcinoid tumor of the ascending colon | — | HCC22 |
| D3A.023 | Benign carcinoid tumor of the transverse colon | — | HCC22 |
| D3A.024 | Benign carcinoid tumor of the descending colon | — | HCC22 |
| D3A.025 | Benign carcinoid tumor of the sigmoid colon | — | HCC22 |
| D3A.026 | Benign carcinoid tumor of the rectum | — | HCC22 |
| D3A.029 | Benign carcinoid tumor of the large intestine, unsp portion | — | HCC22 |
| D3A.090 | Benign carcinoid tumor of the bronchus and lung | — | HCC22 |
| D3A.091 | Benign carcinoid tumor of the thymus | — | HCC22 |
| D3A.092 | Benign carcinoid tumor of the stomach | — | HCC22 |
| D3A.093 | Benign carcinoid tumor of the kidney | — | HCC22 |
| D3A.094 | Benign carcinoid tumor of the foregut, unspecified | — | HCC22 |
| D3A.095 | Benign carcinoid tumor of the midgut, unspecified | — | HCC22 |
| D3A.096 | Benign carcinoid tumor of the hindgut, unspecified | — | HCC22 |
| D3A.098 | Benign carcinoid tumors of other sites | — | HCC22 |
| D3A.8 | Other benign neuroendocrine tumors | — | HCC22 |
| D64.4 | Congenital dyserythropoietic anemia | — | HCC109 |
| D86.3 | Sarcoidosis of skin | — | HCC387 |
| D86.86 | Sarcoid arthropathy | — | HCC93 |
| D86.87 | Sarcoid myositis | — | HCC93 |
| E83.00 | Disorder of copper metabolism, unspecified | — | HCC50 |
| E83.01 | Wilson's disease | — | HCC50 |
| E83.09 | Other disorders of copper metabolism | — | HCC50 |
| E83.31 | Familial hypophosphatemia | — | HCC50 |
| F50.00 | Anorexia nervosa, unspecified | — | HCC153 |
| F50.01 | Anorexia nervosa, restricting type | — | HCC153 |
| F50.010 | Anorexia nervosa, restricting type, mild | — | HCC153 |
| F50.011 | Anorexia nervosa, restricting type, moderate | — | HCC153 |
| F50.012 | Anorexia nervosa, restricting type, severe | — | HCC153 |
| F50.013 | Anorexia nervosa, restricting type, extreme | — | HCC153 |
| F50.014 | Anorexia nervosa, restricting type, in remission | — | HCC153 |
| F50.019 | Anorexia nervosa, restricting type, unspecified | — | HCC153 |
| F50.02 | Anorexia nervosa, binge eating/purging type | — | HCC153 |
| F50.020 | Anorexia nervosa, binge eating/purging type, mild | — | HCC153 |
| F50.021 | Anorexia nervosa, binge eating/purging type, moderate | — | HCC153 |
| F50.022 | Anorexia nervosa, binge eating/purging type, severe | — | HCC153 |
| F50.023 | Anorexia nervosa, binge eating/purging type, extreme | — | HCC153 |
| F50.024 | Anorexia nervosa, binge eating/purging type, in remission | — | HCC153 |
| F50.029 | Anorexia nervosa, binge eating/purging type, unspecified | — | HCC153 |
| F50.2 | Bulimia nervosa | — | HCC153 |
| F50.20 | Bulimia nervosa, unspecified | — | HCC153 |
| F50.21 | Bulimia nervosa, mild | — | HCC153 |
| F50.22 | Bulimia nervosa, moderate | — | HCC153 |
| F50.23 | Bulimia nervosa, severe | — | HCC153 |
| F50.24 | Bulimia nervosa, extreme | — | HCC153 |
| F50.25 | Bulimia nervosa, in remission | — | HCC153 |
| G14 | Postpolio syndrome | — | HCC182 |
| G72.41 | Inclusion body myositis [IBM] | — | HCC93 |
| H34.8110 | Central retinal vein occls, right eye, with macular edema | — | HCC298 |
| H34.8111 | Central retinal vein occlusion, right eye, w rtnl neovas | — | HCC298 |
| H34.8112 | Central retinal vein occlusion, right eye, stable | — | HCC298 |
| H34.8120 | Central retinal vein occlusion, left eye, with macular edema | — | HCC298 |
| H34.8121 | Central retinal vein occlusion, left eye, w rtnl neovas | — | HCC298 |
| H34.8122 | Central retinal vein occlusion, left eye, stable | — | HCC298 |
Showing the first 60 of 228, in code order. Every code page carries its own mapping in every loaded model.
