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_HCC399 | 0.199 |
| Community, non-dual, disabled | CND_HCC399 | 0.150 |
| Community, full-benefit dual, aged | CFA_HCC399 | 0.349 |
| Community, full-benefit dual, disabled | CFD_HCC399 | 0.190 |
| Community, partial-benefit dual, aged | CPA_HCC399 | 0.128 |
| Community, partial-benefit dual, disabled | CPD_HCC399 | 0.052 |
| Long-term institutional | INS_HCC399 | 0.085 |
Hierarchy
Hierarchical condition categories pay only the most severe manifestation of a disease. When HCC 397 (Major Head Injury with Loss of Consciousness > 1 Hour) or HCC 398 (Major Head Injury with Loss of Consciousness < 1 Hour or Unspecified) is also documented for the same beneficiary, HCC 399 is dropped from the score.
ICD-10-CM codes that map to HCC 399
189 codes map to this category in the PY2027 initial mapping, concentrated in the S02 (148), S06 (40), P12 (1) 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 |
|---|---|
| P122 | Epicranial subaponeurotic hemorrhage due to birth injury |
| S020XXA | Fracture of vault of skull, initial encounter for closed fracture |
| S020XXB | Fracture of vault of skull, initial encounter for open fracture |
| S02101A | Fracture of base of skull, right side, initial encounter for closed fracture |
| S02101B | Fracture of base of skull, right side, initial encounter for open fracture |
| S02102A | Fracture of base of skull, left side, initial encounter for closed fracture |
| S02102B | Fracture of base of skull, left side, initial encounter for open fracture |
| S02109A | Fracture of base of skull, unspecified side, initial encounter for closed fracture |
| S02109B | Fracture of base of skull, unspecified side, initial encounter for open fracture |
| S02110A | Type I occipital condyle fracture, unspecified side, initial encounter for closed fracture |
| S02110B | Type I occipital condyle fracture, unspecified side, initial encounter for open fracture |
| S02111A | Type II occipital condyle fracture, unspecified side, initial encounter for closed fracture |
| S02111B | Type II occipital condyle fracture, unspecified side, initial encounter for open fracture |
| S02112A | Type III occipital condyle fracture, unspecified side, initial encounter for closed fracture |
| S02112B | Type III occipital condyle fracture, unspecified side, initial encounter for open fracture |
| S02113A | Unspecified occipital condyle fracture, initial encounter for closed fracture |
| S02113B | Unspecified occipital condyle fracture, initial encounter for open fracture |
| S02118A | Other fracture of occiput, unspecified side, initial encounter for closed fracture |
| S02118B | Other fracture of occiput, unspecified side, initial encounter for open fracture |
| S02119A | Unspecified fracture of occiput, initial encounter for closed fracture |
| S02119B | Unspecified fracture of occiput, initial encounter for open fracture |
| S0211AA | Type I occipital condyle fracture, right side, initial encounter for closed fracture |
| S0211AB | Type I occipital condyle fracture, right side, initial encounter for open fracture |
| S0211BA | Type I occipital condyle fracture, left side, initial encounter for closed fracture |
| S0211BB | Type I occipital condyle fracture, left side, initial encounter for open fracture |
| S0211CA | Type II occipital condyle fracture, right side, initial encounter for closed fracture |
| S0211CB | Type II occipital condyle fracture, right side, initial encounter for open fracture |
| S0211DA | Type II occipital condyle fracture, left side, initial encounter for closed fracture |
| S0211DB | Type II occipital condyle fracture, left side, initial encounter for open fracture |
| S0211EA | Type III occipital condyle fracture, right side, initial encounter for closed fracture |
| S0211EB | Type III occipital condyle fracture, right side, initial encounter for open fracture |
| S0211FA | Type III occipital condyle fracture, left side, initial encounter for closed fracture |
| S0211FB | Type III occipital condyle fracture, left side, initial encounter for open fracture |
| S0211GA | Other fracture of occiput, right side, initial encounter for closed fracture |
| S0211GB | Other fracture of occiput, right side, initial encounter for open fracture |
| S0211HA | Other fracture of occiput, left side, initial encounter for closed fracture |
| S0211HB | Other fracture of occiput, left side, initial encounter for open fracture |
| S02121A | Fracture of orbital roof, right side, initial encounter for closed fracture |
| S02121B | Fracture of orbital roof, right side, initial encounter for open fracture |
| S02122A | Fracture of orbital roof, left side, initial encounter for closed fracture |
| S02122B | Fracture of orbital roof, left side, initial encounter for open fracture |
| S02129A | Fracture of orbital roof, unspecified side, initial encounter for closed fracture |
| S02129B | Fracture of orbital roof, unspecified side, initial encounter for open fracture |
| S0219XA | Other fracture of base of skull, initial encounter for closed fracture |
| S0219XB | Other fracture of base of skull, initial encounter for open fracture |
| S0230XA | Fracture of orbital floor, unspecified side, initial encounter for closed fracture |
| S0230XB | Fracture of orbital floor, unspecified side, initial encounter for open fracture |
| S0231XA | Fracture of orbital floor, right side, initial encounter for closed fracture |
| S0231XB | Fracture of orbital floor, right side, initial encounter for open fracture |
| S0232XA | Fracture of orbital floor, left side, initial encounter for closed fracture |
| S0232XB | Fracture of orbital floor, left side, initial encounter for open fracture |
| S02400A | Malar fracture, unspecified side, initial encounter for closed fracture |
| S02400B | Malar fracture, unspecified side, initial encounter for open fracture |
| S02401A | Maxillary fracture, unspecified side, initial encounter for closed fracture |
| S02401B | Maxillary fracture, unspecified side, initial encounter for open fracture |
| S02402A | Zygomatic fracture, unspecified side, initial encounter for closed fracture |
| S02402B | Zygomatic fracture, unspecified side, initial encounter for open fracture |
| S0240AA | Malar fracture, right side, initial encounter for closed fracture |
| S0240AB | Malar fracture, right side, initial encounter for open fracture |
| S0240BA | Malar fracture, left side, initial encounter for closed fracture |
| S0240BB | Malar fracture, left side, initial encounter for open fracture |
| S0240CA | Maxillary fracture, right side, initial encounter for closed fracture |
| S0240CB | Maxillary fracture, right side, initial encounter for open fracture |
| S0240DA | Maxillary fracture, left side, initial encounter for closed fracture |
| S0240DB | Maxillary fracture, left side, initial encounter for open fracture |
| S0240EA | Zygomatic fracture, right side, initial encounter for closed fracture |
| S0240EB | Zygomatic fracture, right side, initial encounter for open fracture |
| S0240FA | Zygomatic fracture, left side, initial encounter for closed fracture |
| S0240FB | Zygomatic fracture, left side, initial encounter for open fracture |
| S02411A | LeFort I fracture, initial encounter for closed fracture |
| S02411B | LeFort I fracture, initial encounter for open fracture |
| S02412A | LeFort II fracture, initial encounter for closed fracture |
| S02412B | LeFort II fracture, initial encounter for open fracture |
| S02413A | LeFort III fracture, initial encounter for closed fracture |
| S02413B | LeFort III fracture, initial encounter for open fracture |
| S0242XA | Fracture of alveolus of maxilla, initial encounter for closed fracture |
| S0242XB | Fracture of alveolus of maxilla, initial encounter for open fracture |
| S02600A | Fracture of unspecified part of body of mandible, unspecified side, initial encounter for closed fracture |
| S02600B | Fracture of unspecified part of body of mandible, unspecified side, initial encounter for open fracture |
| S02601A | Fracture of unspecified part of body of right mandible, initial encounter for closed fracture |
| S02601B | Fracture of unspecified part of body of right mandible, initial encounter for open fracture |
| S02602A | Fracture of unspecified part of body of left mandible, initial encounter for closed fracture |
| S02602B | Fracture of unspecified part of body of left mandible, initial encounter for open fracture |
| S02609A | Fracture of mandible, unspecified, initial encounter for closed fracture |
| S02609B | Fracture of mandible, unspecified, initial encounter for open fracture |
| S02610A | Fracture of condylar process of mandible, unspecified side, initial encounter for closed fracture |
| S02610B | Fracture of condylar process of mandible, unspecified side, initial encounter for open fracture |
| S02611A | Fracture of condylar process of right mandible, initial encounter for closed fracture |
| S02611B | Fracture of condylar process of right mandible, initial encounter for open fracture |
| S02612A | Fracture of condylar process of left mandible, initial encounter for closed fracture |
| S02612B | Fracture of condylar process of left mandible, initial encounter for open fracture |
| S02620A | Fracture of subcondylar process of mandible, unspecified side, initial encounter for closed fracture |
| S02620B | Fracture of subcondylar process of mandible, unspecified side, initial encounter for open fracture |
| S02621A | Fracture of subcondylar process of right mandible, initial encounter for closed fracture |
| S02621B | Fracture of subcondylar process of right mandible, initial encounter for open fracture |
| S02622A | Fracture of subcondylar process of left mandible, initial encounter for closed fracture |
| S02622B | Fracture of subcondylar process of left mandible, initial encounter for open fracture |
| S02630A | Fracture of coronoid process of mandible, unspecified side, initial encounter for closed fracture |
| S02630B | Fracture of coronoid process of mandible, unspecified side, initial encounter for open fracture |
| S02631A | Fracture of coronoid process of right mandible, initial encounter for closed fracture |
| S02631B | Fracture of coronoid process of right mandible, initial encounter for open fracture |
| S02632A | Fracture of coronoid process of left mandible, initial encounter for closed fracture |
| S02632B | Fracture of coronoid process of left mandible, initial encounter for open fracture |
| S02640A | Fracture of ramus of mandible, unspecified side, initial encounter for closed fracture |
| S02640B | Fracture of ramus of mandible, unspecified side, initial encounter for open fracture |
| S02641A | Fracture of ramus of right mandible, initial encounter for closed fracture |
| S02641B | Fracture of ramus of right mandible, initial encounter for open fracture |
| S02642A | Fracture of ramus of left mandible, initial encounter for closed fracture |
| S02642B | Fracture of ramus of left mandible, initial encounter for open fracture |
| S02650A | Fracture of angle of mandible, unspecified side, initial encounter for closed fracture |
| S02650B | Fracture of angle of mandible, unspecified side, initial encounter for open fracture |
| S02651A | Fracture of angle of right mandible, initial encounter for closed fracture |
| S02651B | Fracture of angle of right mandible, initial encounter for open fracture |
| S02652A | Fracture of angle of left mandible, initial encounter for closed fracture |
| S02652B | Fracture of angle of left mandible, initial encounter for open fracture |
| S0266XA | Fracture of symphysis of mandible, initial encounter for closed fracture |
| S0266XB | Fracture of symphysis of mandible, initial encounter for open fracture |
| S02670A | Fracture of alveolus of mandible, unspecified side, initial encounter for closed fracture |
| S02670B | Fracture of alveolus of mandible, unspecified side, initial encounter for open fracture |
| S02671A | Fracture of alveolus of right mandible, initial encounter for closed fracture |
| S02671B | Fracture of alveolus of right mandible, initial encounter for open fracture |
| S02672A | Fracture of alveolus of left mandible, initial encounter for closed fracture |
| S02672B | Fracture of alveolus of left mandible, initial encounter for open fracture |
| S0269XA | Fracture of mandible of other specified site, initial encounter for closed fracture |
| S0269XB | Fracture of mandible of other specified site, initial encounter for open fracture |
| S0280XA | Fracture of other specified skull and facial bones, unspecified side, initial encounter for closed fracture |
| S0280XB | Fracture of other specified skull and facial bones, unspecified side, initial encounter for open fracture |
| S0281XA | Fracture of other specified skull and facial bones, right side, initial encounter for closed fracture |
| S0281XB | Fracture of other specified skull and facial bones, right side, initial encounter for open fracture |
| S0282XA | Fracture of other specified skull and facial bones, left side, initial encounter for closed fracture |
| S0282XB | Fracture of other specified skull and facial bones, left side, initial encounter for open fracture |
| S02831A | Fracture of medial orbital wall, right side, initial encounter for closed fracture |
| S02831B | Fracture of medial orbital wall, right side, initial encounter for open fracture |
| S02832A | Fracture of medial orbital wall, left side, initial encounter for closed fracture |
| S02832B | Fracture of medial orbital wall, left side, initial encounter for open fracture |
| S02839A | Fracture of medial orbital wall, unspecified side, initial encounter for closed fracture |
| S02839B | Fracture of medial orbital wall, unspecified side, initial encounter for open fracture |
| S02841A | Fracture of lateral orbital wall, right side, initial encounter for closed fracture |
| S02841B | Fracture of lateral orbital wall, right side, initial encounter for open fracture |
| S02842A | Fracture of lateral orbital wall, left side, initial encounter for closed fracture |
| S02842B | Fracture of lateral orbital wall, left side, initial encounter for open fracture |
| S02849A | Fracture of lateral orbital wall, unspecified side, initial encounter for closed fracture |
| S02849B | Fracture of lateral orbital wall, unspecified side, initial encounter for open fracture |
| S0285XA | Fracture of orbit, unspecified, initial encounter for closed fracture |
| S0285XB | Fracture of orbit, unspecified, initial encounter for open fracture |
| S0291XA | Unspecified fracture of skull, initial encounter for closed fracture |
| S0291XB | Unspecified fracture of skull, initial encounter for open fracture |
| S0292XA | Unspecified fracture of facial bones, initial encounter for closed fracture |
| S0292XB | Unspecified fracture of facial bones, initial encounter for open fracture |
| S061X0A | Traumatic cerebral edema without loss of consciousness, initial encounter |
| S061XAA | Traumatic cerebral edema with loss of consciousness status unknown, initial encounter |
| S062X0A | Diffuse traumatic brain injury without loss of consciousness, initial encounter |
| S062XAA | Diffuse traumatic brain injury with loss of consciousness status unknown, initial encounter |
| S06300A | Unspecified focal traumatic brain injury without loss of consciousness, initial encounter |
| S0630AA | Unspecified focal traumatic brain injury with loss of consciousness status unknown, initial encounter |
| S06310A | Contusion and laceration of right cerebrum without loss of consciousness, initial encounter |
| S0631AA | Contusion and laceration of right cerebrum with loss of consciousness status unknown, initial encounter |
| S06320A | Contusion and laceration of left cerebrum without loss of consciousness, initial encounter |
| S0632AA | Contusion and laceration of left cerebrum with loss of consciousness status unknown, initial encounter |
| S06330A | Contusion and laceration of cerebrum, unspecified, without loss of consciousness, initial encounter |
| S0633AA | Contusion and laceration of cerebrum, unspecified, with loss of consciousness status unknown, initial encounter |
| S06340A | Traumatic hemorrhage of right cerebrum without loss of consciousness, initial encounter |
| S0634AA | Traumatic hemorrhage of right cerebrum with loss of consciousness status unknown, initial encounter |
| S06350A | Traumatic hemorrhage of left cerebrum without loss of consciousness, initial encounter |
| S0635AA | Traumatic hemorrhage of left cerebrum with loss of consciousness status unknown, initial encounter |
| S06360A | Traumatic hemorrhage of cerebrum, unspecified, without loss of consciousness, initial encounter |
| S0636AA | Traumatic hemorrhage of cerebrum, unspecified, with loss of consciousness status unknown, initial encounter |
| S06370A | Contusion, laceration, and hemorrhage of cerebellum without loss of consciousness, initial encounter |
| S0637AA | Contusion, laceration, and hemorrhage of cerebellum with loss of consciousness status unknown, initial encounter |
| S06380A | Contusion, laceration, and hemorrhage of brainstem without loss of consciousness, initial encounter |
| S0638AA | Contusion, laceration, and hemorrhage of brainstem with loss of consciousness status unknown, initial encounter |
| S064X0A | Epidural hemorrhage without loss of consciousness, initial encounter |
| S064XAA | Epidural hemorrhage with loss of consciousness status unknown, initial encounter |
| S065X0A | Traumatic subdural hemorrhage without loss of consciousness, initial encounter |
| S065XAA | Traumatic subdural hemorrhage with loss of consciousness status unknown, initial encounter |
| S066X0A | Traumatic subarachnoid hemorrhage without loss of consciousness, initial encounter |
| S066XAA | Traumatic subarachnoid hemorrhage with loss of consciousness status unknown, initial encounter |
| S06810A | Injury of right internal carotid artery, intracranial portion, not elsewhere classified without loss of consciousness, initial encounter |
| S0681AA | Injury of right internal carotid artery, intracranial portion, not elsewhere classified with loss of consciousness status unknown, initial encounter |
| S06820A | Injury of left internal carotid artery, intracranial portion, not elsewhere classified without loss of consciousness, initial encounter |
| S0682AA | Injury of left internal carotid artery, intracranial portion, not elsewhere classified with loss of consciousness status unknown, initial encounter |
| S06890A | Other specified intracranial injury without loss of consciousness, initial encounter |
| S0689AA | Other specified intracranial injury with loss of consciousness status unknown, initial encounter |
| S068A0A | Primary blast injury of brain, not elsewhere classified without loss of consciousness, initial encounter |
| S068AAA | Primary blast injury of brain, not elsewhere classified with loss of consciousness status unknown, initial encounter |
| S069X0A | Unspecified intracranial injury without loss of consciousness, initial encounter |
| S069XAA | Unspecified intracranial injury with loss of consciousness status unknown, initial encounter |
| S06A0XA | Traumatic brain compression without herniation, initial encounter |
| S06A1XA | Traumatic brain compression with herniation, initial encounter |
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 |
|---|---|
| 167 | 188 |
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 399?
189 ICD-10-CM codes map to HCC 399 in the CMS PY2027 initial mapping, for example P122 Epicranial subaponeurotic hemorrhage due to birth injury; S020XXA Fracture of vault of skull, initial encounter for closed fracture; S020XXB Fracture of vault of skull, initial encounter for open fracture; S02101A Fracture of base of skull, right side, initial encounter for closed fracture. 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 399 add to a risk score?
The V28 relative factor for HCC 399 is 0.199 for a community, non-dual, aged beneficiary, 0.349 for full-benefit dual aged, 0.150 for non-dual disabled and 0.085 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 399 count together with related categories?
No. Within a hierarchy only the most severe category is paid. HCC 399 is dropped when HCC 397 (Major Head Injury with Loss of Consciousness > 1 Hour) or HCC 398 (Major Head Injury with Loss of Consciousness < 1 Hour or Unspecified) is also present.
What has to be documented for HCC 399 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.