Relative factors by segment
Each segment is a separate regression; the factor is added to the beneficiary's demographic factors and other categories, then normalized and reduced by the coding intensity adjustment before it meets the plan's base rate. A factor of 1.000 equals the expected cost of an average beneficiary.
| Segment | Model code | Relative factor |
|---|---|---|
| Community, non-dual, aged | CNA_HCC17 | 4.209 |
| Community, non-dual, disabled | CND_HCC17 | 3.995 |
| Community, full-benefit dual, aged | CFA_HCC17 | 3.896 |
| Community, full-benefit dual, disabled | CFD_HCC17 | 4.235 |
| Community, partial-benefit dual, aged | CPA_HCC17 | 3.946 |
| Community, partial-benefit dual, disabled | CPD_HCC17 | 4.103 |
| Long-term institutional | INS_HCC17 | 1.952 |
Hierarchy
Hierarchical condition categories pay only the most severe manifestation of a disease. HCC 17 is the most severe category in its hierarchy. When HCC 17 is present it drops HCC 18 (Cancer Metastatic to Bone, Other and Unspecified Metastatic Cancer; Acute Leukemia Except Myeloid), HCC 19 (Myelodysplastic Syndromes, Multiple Myeloma, and Other Cancers), HCC 20 (Lung and Other Severe Cancers), HCC 21 (Lymphoma and Other Cancers), HCC 22 (Bladder, Colorectal, and Other Cancers), HCC 23 (Prostate, Breast, and Other Cancers and Tumors), so documenting the less severe condition alongside it adds nothing to payment but still matters for the clinical record.
ICD-10-CM codes that map to HCC 17
78 codes map to this category in the PY2027 initial mapping, concentrated in the C92 (15), C78 (13), C84 (11), C79 (10), C94 (9), C7B (8) code families. Descriptions are the CMS mapping descriptions for the FY2026 code set; a code that is deleted or split in the October code update stays valid for dates of service before the change.
| ICD-10-CM | Description |
|---|---|
| C771 | Secondary and unspecified malignant neoplasm of intrathoracic lymph nodes |
| C778 | Secondary and unspecified malignant neoplasm of lymph nodes of multiple regions |
| C7800 | Secondary malignant neoplasm of unspecified lung |
| C7801 | Secondary malignant neoplasm of right lung |
| C7802 | Secondary malignant neoplasm of left lung |
| C781 | Secondary malignant neoplasm of mediastinum |
| C782 | Secondary malignant neoplasm of pleura |
| C7830 | Secondary malignant neoplasm of unspecified respiratory organ |
| C7839 | Secondary malignant neoplasm of other respiratory organs |
| C784 | Secondary malignant neoplasm of small intestine |
| C785 | Secondary malignant neoplasm of large intestine and rectum |
| C786 | Secondary malignant neoplasm of retroperitoneum and peritoneum |
| C787 | Secondary malignant neoplasm of liver and intrahepatic bile duct |
| C7880 | Secondary malignant neoplasm of unspecified digestive organ |
| C7889 | Secondary malignant neoplasm of other digestive organs |
| C7900 | Secondary malignant neoplasm of unspecified kidney and renal pelvis |
| C7901 | Secondary malignant neoplasm of right kidney and renal pelvis |
| C7902 | Secondary malignant neoplasm of left kidney and renal pelvis |
| C7931 | Secondary malignant neoplasm of brain |
| C7932 | Secondary malignant neoplasm of cerebral meninges |
| C7940 | Secondary malignant neoplasm of unspecified part of nervous system |
| C7949 | Secondary malignant neoplasm of other parts of nervous system |
| C7970 | Secondary malignant neoplasm of unspecified adrenal gland |
| C7971 | Secondary malignant neoplasm of right adrenal gland |
| C7972 | Secondary malignant neoplasm of left adrenal gland |
| C7B00 | Secondary carcinoid tumors, unspecified site |
| C7B01 | Secondary carcinoid tumors of distant lymph nodes |
| C7B02 | Secondary carcinoid tumors of liver |
| C7B03 | Secondary carcinoid tumors of bone |
| C7B04 | Secondary carcinoid tumors of peritoneum |
| C7B09 | Secondary carcinoid tumors of other sites |
| C7B1 | Secondary Merkel cell carcinoma |
| C7B8 | Other secondary neuroendocrine tumors |
| C8410 | Sezary disease, unspecified site |
| C8411 | Sezary disease, lymph nodes of head, face, and neck |
| C8412 | Sezary disease, intrathoracic lymph nodes |
| C8413 | Sezary disease, intra-abdominal lymph nodes |
| C8414 | Sezary disease, lymph nodes of axilla and upper limb |
| C8415 | Sezary disease, lymph nodes of inguinal region and lower limb |
| C8416 | Sezary disease, intrapelvic lymph nodes |
| C8417 | Sezary disease, spleen |
| C8418 | Sezary disease, lymph nodes of multiple sites |
| C8419 | Sezary disease, extranodal and solid organ sites |
| C841A | Sezary disease, in remission |
| C9200 | Acute myeloblastic leukemia, not having achieved remission |
| C9201 | Acute myeloblastic leukemia, in remission |
| C9202 | Acute myeloblastic leukemia, in relapse |
| C9230 | Myeloid sarcoma, not having achieved remission |
| C9231 | Myeloid sarcoma, in remission |
| C9232 | Myeloid sarcoma, in relapse |
| C9250 | Acute myelomonocytic leukemia, not having achieved remission |
| C9251 | Acute myelomonocytic leukemia, in remission |
| C9252 | Acute myelomonocytic leukemia, in relapse |
| C9260 | Acute myeloid leukemia with 11q23-abnormality not having achieved remission |
| C9261 | Acute myeloid leukemia with 11q23-abnormality in remission |
| C9262 | Acute myeloid leukemia with 11q23-abnormality in relapse |
| C92A0 | Acute myeloid leukemia with multilineage dysplasia, not having achieved remission |
| C92A1 | Acute myeloid leukemia with multilineage dysplasia, in remission |
| C92A2 | Acute myeloid leukemia with multilineage dysplasia, in relapse |
| C9300 | Acute monoblastic/monocytic leukemia, not having achieved remission |
| C9301 | Acute monoblastic/monocytic leukemia, in remission |
| C9302 | Acute monoblastic/monocytic leukemia, in relapse |
| C9400 | Acute erythroid leukemia, not having achieved remission |
| C9401 | Acute erythroid leukemia, in remission |
| C9402 | Acute erythroid leukemia, in relapse |
| C9420 | Acute megakaryoblastic leukemia not having achieved remission |
| C9421 | Acute megakaryoblastic leukemia, in remission |
| C9422 | Acute megakaryoblastic leukemia, in relapse |
| C9440 | Acute panmyelosis with myelofibrosis not having achieved remission |
| C9441 | Acute panmyelosis with myelofibrosis, in remission |
| C9442 | Acute panmyelosis with myelofibrosis, in relapse |
| D4622 | Refractory anemia with excess of blasts 2 |
| E3400 | Carcinoid syndrome, unspecified |
| E3401 | Carcinoid heart syndrome |
| E3409 | Other carcinoid syndrome |
| I3131 | Malignant pericardial effusion in diseases classified elsewhere |
| J910 | Malignant pleural effusion |
| R180 | Malignant ascites |
Where these codes sat in the V22 model
The V28 recalibration renumbered and regrouped categories; this table shows which legacy V22 categories the same ICD-10 codes belonged to, which is the quickest way to reconcile a V22-era HCC gap list with the current model.
| V22 HCC | Codes |
|---|---|
| 8 | 57 |
| 10 | 11 |
| 9 | 3 |
| 12 | 3 |
| 46 | 1 |
Capturing and defending the category
A category counts for a payment year when a mapped diagnosis is documented at least once during the data collection year by an acceptable provider type at a face-to-face or audio-video encounter, and when the note shows the condition was monitored, evaluated, assessed or treated. Chronic conditions do not carry forward: a category that is not re-documented in the year drops out of the score, which is why annual wellness visits and problem-list reconciliation are where most recapture happens. Risk adjustment data validation audits sample enrollees and ask for the medical record behind each submitted category; an unsupported category is removed and, under the extrapolation rules, the error rate is applied across the contract. The QuickIntell risk adjustment product surfaces suspected and unsupported categories from the chart, and the HCC hub lists every V28 category with its factor and code count.
Frequently asked questions
Which ICD-10 codes map to HCC 17?
78 ICD-10-CM codes map to HCC 17 in the CMS PY2027 initial mapping, for example C771 Secondary and unspecified malignant neoplasm of intrathoracic lymph nodes; C778 Secondary and unspecified malignant neoplasm of lymph nodes of multiple regions; C7800 Secondary malignant neoplasm of unspecified lung; C7801 Secondary malignant neoplasm of right lung. The full list is on this page; a code counts only when it is documented at a face-to-face or video encounter in the data collection year and supported by the record.
How much does HCC 17 add to a risk score?
The V28 relative factor for HCC 17 is 4.209 for a community, non-dual, aged beneficiary, 3.896 for full-benefit dual aged, 3.995 for non-dual disabled and 1.952 for long-term institutional members. A factor of 1.000 equals the expected annual cost of an average beneficiary, so the category's share of the payment follows the plan's base rate for that segment.
Does HCC 17 count together with related categories?
No. Within a hierarchy only the most severe category is paid. HCC 17 is the most severe category in its hierarchy, and it drops HCC 18, HCC 19, HCC 20, HCC 21, HCC 22, HCC 23 when it is present.
What has to be documented for HCC 17 to be valid?
The diagnosis must be recorded by an acceptable provider type during a face-to-face or audio-video encounter in the service year, with the note showing that the condition was monitored, evaluated, assessed or treated. Risk adjustment data validation audits recover payment for categories the record does not support, so the code on the claim and the assessment in the note must match.
Sources
Every figure on this page is taken from the CMS publications below, as released by the Centers for Medicare & Medicaid Services. Projection built 2026-10-02. Verify against the primary file before billing or contracting decisions.
- ICD-10-CM to CMS-HCC V28 mappings, payment year 2027 initialVersion PY2027 initial ICD-10-CM mappings (dates of service 2026) · effective 2027-01-01 · file 2027 Initial ICD-10-CM Mappings.csvSHA-256 9c260b06d0dd2806…
- CMS-HCC V28 model software: labels, hierarchies and relative factorsVersion CMS-HCC V28 software V2826.115.T2 (PY2027 initial) · effective 2027-01-01 · file C2824T2N.csvSHA-256 20f38d537493b41c…
Disclaimer
Relative factors and mappings are reproduced from the CMS risk adjustment model files as an operational reference. Payment depends on the plan's base rate, normalization, the coding intensity adjustment and the enrollee's segment. Not legal, clinical or billing advice.