CMS-HCC Risk Adjustment · V28 Model · Payment Year 2026 189 Codes

HCC 399: Major Head Injury without Loss of Consciousness ICD-10-CM

Q: What is HCC 399 in the CMS-HCC model?

HCC 399 is CMS-HCC Category 399 (Major Head Injury without Loss of Consciousness) in the V28 risk adjustment model. It covers 189 ICD-10-CM diagnosis codes that raise a Medicare Advantage beneficiary's risk score when documented.

Q: What is the RAF weight for HCC 399?

For payment year 2026, HCC 399 adds 0.199 to the RAF score of a community, non-dual, aged beneficiary. The published weights range from 0.052 to 0.349 across the seven payment segments shown above.

CMS-HCC Category 399 (Major Head Injury without Loss of Consciousness) is a payment HCC in the V28 Medicare Advantage risk adjustment model. For payment year 2026 it adds a risk adjustment factor between 0.052 and 0.349 to a beneficiary's RAF score depending on the payment segment (0.199 for a community, non-dual, aged enrollee). 189 ICD-10-CM diagnosis codes map to HCC 399. A more severe related category (HCC 397 and HCC 398) supersedes it when both are reported.

✓ Built from the official CMS PY 2026 risk adjustment filesV28 pays 100% of MA risk scores from PY 2026

+0.199

RAF, Community Non-Dual Aged

189

ICD-10-CM Codes

HCC 397

Superseded By

PY 2026

Dataset

CMS-HCC V28

RAF Weight by Payment Segment 7 segments

Payment Segment	Relative Factor
Community, non-dual, aged	0.199
Community, partial-benefit dual, aged	0.128
Community, full-benefit dual, aged	0.349
Community, non-dual, disabled	0.150
Community, partial-benefit dual, disabled	0.052
Community, full-benefit dual, disabled	0.190
Institutional	0.085

A beneficiary is scored in exactly one segment, set by Medicaid (dual) status, aged or disabled entitlement, and residence. Factors are relative weights, not dollar amounts; new-enrollee segments score on demographics only. In the hierarchy, HCC 397 (Major Head Injury with Loss of Consciousness > 1 Hour) and HCC 398 (Major Head Injury with Loss of Consciousness < 1 Hour or Unspecified) supersede HCC 399 when reported together.

ICD-10-CM

ICD-10-CM Codes That Map to HCC 399 189 codes

189 of 189 shown

P12.2 Epicranial subaponeurotic hemorrhage due to birth injury new to V28
S02.0XXA Fracture of vault of skull, initial encounter for closed fracture from V24 HCC 167
S02.0XXB Fracture of vault of skull, initial encounter for open fracture from V24 HCC 167
S02.101A Fracture of base of skull, right side, initial encounter for closed fracture from V24 HCC 167
S02.101B Fracture of base of skull, right side, initial encounter for open fracture from V24 HCC 167
S02.102A Fracture of base of skull, left side, initial encounter for closed fracture from V24 HCC 167
S02.102B Fracture of base of skull, left side, initial encounter for open fracture from V24 HCC 167
S02.109A Fracture of base of skull, unspecified side, initial encounter for closed fracture from V24 HCC 167
S02.109B Fracture of base of skull, unspecified side, initial encounter for open fracture from V24 HCC 167
S02.110A Type I occipital condyle fracture, unspecified side, initial encounter for closed fracture from V24 HCC 167
S02.110B Type I occipital condyle fracture, unspecified side, initial encounter for open fracture from V24 HCC 167
S02.111A Type II occipital condyle fracture, unspecified side, initial encounter for closed fracture from V24 HCC 167
S02.111B Type II occipital condyle fracture, unspecified side, initial encounter for open fracture from V24 HCC 167
S02.112A Type III occipital condyle fracture, unspecified side, initial encounter for closed fracture from V24 HCC 167
S02.112B Type III occipital condyle fracture, unspecified side, initial encounter for open fracture from V24 HCC 167
S02.113A Unspecified occipital condyle fracture, initial encounter for closed fracture from V24 HCC 167
S02.113B Unspecified occipital condyle fracture, initial encounter for open fracture from V24 HCC 167
S02.118A Other fracture of occiput, unspecified side, initial encounter for closed fracture from V24 HCC 167
S02.118B Other fracture of occiput, unspecified side, initial encounter for open fracture from V24 HCC 167
S02.119A Unspecified fracture of occiput, initial encounter for closed fracture from V24 HCC 167
S02.119B Unspecified fracture of occiput, initial encounter for open fracture from V24 HCC 167
S02.11AA Type I occipital condyle fracture, right side, initial encounter for closed fracture from V24 HCC 167
S02.11AB Type I occipital condyle fracture, right side, initial encounter for open fracture from V24 HCC 167
S02.11BA Type I occipital condyle fracture, left side, initial encounter for closed fracture from V24 HCC 167
S02.11BB Type I occipital condyle fracture, left side, initial encounter for open fracture from V24 HCC 167
S02.11CA Type II occipital condyle fracture, right side, initial encounter for closed fracture from V24 HCC 167
S02.11CB Type II occipital condyle fracture, right side, initial encounter for open fracture from V24 HCC 167
S02.11DA Type II occipital condyle fracture, left side, initial encounter for closed fracture from V24 HCC 167
S02.11DB Type II occipital condyle fracture, left side, initial encounter for open fracture from V24 HCC 167
S02.11EA Type III occipital condyle fracture, right side, initial encounter for closed fracture from V24 HCC 167
S02.11EB Type III occipital condyle fracture, right side, initial encounter for open fracture from V24 HCC 167
S02.11FA Type III occipital condyle fracture, left side, initial encounter for closed fracture from V24 HCC 167
S02.11FB Type III occipital condyle fracture, left side, initial encounter for open fracture from V24 HCC 167
S02.11GA Other fracture of occiput, right side, initial encounter for closed fracture from V24 HCC 167
S02.11GB Other fracture of occiput, right side, initial encounter for open fracture from V24 HCC 167
S02.11HA Other fracture of occiput, left side, initial encounter for closed fracture from V24 HCC 167
S02.11HB Other fracture of occiput, left side, initial encounter for open fracture from V24 HCC 167
S02.121A Fracture of orbital roof, right side, initial encounter for closed fracture from V24 HCC 167
S02.121B Fracture of orbital roof, right side, initial encounter for open fracture from V24 HCC 167
S02.122A Fracture of orbital roof, left side, initial encounter for closed fracture from V24 HCC 167
S02.122B Fracture of orbital roof, left side, initial encounter for open fracture from V24 HCC 167
S02.129A Fracture of orbital roof, unspecified side, initial encounter for closed fracture from V24 HCC 167
S02.129B Fracture of orbital roof, unspecified side, initial encounter for open fracture from V24 HCC 167
S02.19XA Other fracture of base of skull, initial encounter for closed fracture from V24 HCC 167
S02.19XB Other fracture of base of skull, initial encounter for open fracture from V24 HCC 167
S02.30XA Fracture of orbital floor, unspecified side, initial encounter for closed fracture from V24 HCC 167
S02.30XB Fracture of orbital floor, unspecified side, initial encounter for open fracture from V24 HCC 167
S02.31XA Fracture of orbital floor, right side, initial encounter for closed fracture from V24 HCC 167
S02.31XB Fracture of orbital floor, right side, initial encounter for open fracture from V24 HCC 167
S02.32XA Fracture of orbital floor, left side, initial encounter for closed fracture from V24 HCC 167
S02.32XB Fracture of orbital floor, left side, initial encounter for open fracture from V24 HCC 167
S02.400A Malar fracture, unspecified side, initial encounter for closed fracture from V24 HCC 167
S02.400B Malar fracture, unspecified side, initial encounter for open fracture from V24 HCC 167
S02.401A Maxillary fracture, unspecified side, initial encounter for closed fracture from V24 HCC 167
S02.401B Maxillary fracture, unspecified side, initial encounter for open fracture from V24 HCC 167
S02.402A Zygomatic fracture, unspecified side, initial encounter for closed fracture from V24 HCC 167
S02.402B Zygomatic fracture, unspecified side, initial encounter for open fracture from V24 HCC 167
S02.40AA Malar fracture, right side, initial encounter for closed fracture from V24 HCC 167
S02.40AB Malar fracture, right side, initial encounter for open fracture from V24 HCC 167
S02.40BA Malar fracture, left side, initial encounter for closed fracture from V24 HCC 167
S02.40BB Malar fracture, left side, initial encounter for open fracture from V24 HCC 167
S02.40CA Maxillary fracture, right side, initial encounter for closed fracture from V24 HCC 167
S02.40CB Maxillary fracture, right side, initial encounter for open fracture from V24 HCC 167
S02.40DA Maxillary fracture, left side, initial encounter for closed fracture from V24 HCC 167
S02.40DB Maxillary fracture, left side, initial encounter for open fracture from V24 HCC 167
S02.40EA Zygomatic fracture, right side, initial encounter for closed fracture from V24 HCC 167
S02.40EB Zygomatic fracture, right side, initial encounter for open fracture from V24 HCC 167
S02.40FA Zygomatic fracture, left side, initial encounter for closed fracture from V24 HCC 167
S02.40FB Zygomatic fracture, left side, initial encounter for open fracture from V24 HCC 167
S02.411A LeFort I fracture, initial encounter for closed fracture from V24 HCC 167
S02.411B LeFort I fracture, initial encounter for open fracture from V24 HCC 167
S02.412A LeFort II fracture, initial encounter for closed fracture from V24 HCC 167
S02.412B LeFort II fracture, initial encounter for open fracture from V24 HCC 167
S02.413A LeFort III fracture, initial encounter for closed fracture from V24 HCC 167
S02.413B LeFort III fracture, initial encounter for open fracture from V24 HCC 167
S02.42XA Fracture of alveolus of maxilla, initial encounter for closed fracture from V24 HCC 167
S02.42XB Fracture of alveolus of maxilla, initial encounter for open fracture from V24 HCC 167
S02.600A Fracture of unspecified part of body of mandible, unspecified side, initial encounter for closed fracture from V24 HCC 167
S02.600B Fracture of unspecified part of body of mandible, unspecified side, initial encounter for open fracture from V24 HCC 167
S02.601A Fracture of unspecified part of body of right mandible, initial encounter for closed fracture from V24 HCC 167
S02.601B Fracture of unspecified part of body of right mandible, initial encounter for open fracture from V24 HCC 167
S02.602A Fracture of unspecified part of body of left mandible, initial encounter for closed fracture from V24 HCC 167
S02.602B Fracture of unspecified part of body of left mandible, initial encounter for open fracture from V24 HCC 167
S02.609A Fracture of mandible, unspecified, initial encounter for closed fracture from V24 HCC 167
S02.609B Fracture of mandible, unspecified, initial encounter for open fracture from V24 HCC 167
S02.610A Fracture of condylar process of mandible, unspecified side, initial encounter for closed fracture from V24 HCC 167
S02.610B Fracture of condylar process of mandible, unspecified side, initial encounter for open fracture from V24 HCC 167
S02.611A Fracture of condylar process of right mandible, initial encounter for closed fracture from V24 HCC 167
S02.611B Fracture of condylar process of right mandible, initial encounter for open fracture from V24 HCC 167
S02.612A Fracture of condylar process of left mandible, initial encounter for closed fracture from V24 HCC 167
S02.612B Fracture of condylar process of left mandible, initial encounter for open fracture from V24 HCC 167
S02.620A Fracture of subcondylar process of mandible, unspecified side, initial encounter for closed fracture from V24 HCC 167
S02.620B Fracture of subcondylar process of mandible, unspecified side, initial encounter for open fracture from V24 HCC 167
S02.621A Fracture of subcondylar process of right mandible, initial encounter for closed fracture from V24 HCC 167
S02.621B Fracture of subcondylar process of right mandible, initial encounter for open fracture from V24 HCC 167
S02.622A Fracture of subcondylar process of left mandible, initial encounter for closed fracture from V24 HCC 167
S02.622B Fracture of subcondylar process of left mandible, initial encounter for open fracture from V24 HCC 167
S02.630A Fracture of coronoid process of mandible, unspecified side, initial encounter for closed fracture from V24 HCC 167
S02.630B Fracture of coronoid process of mandible, unspecified side, initial encounter for open fracture from V24 HCC 167
S02.631A Fracture of coronoid process of right mandible, initial encounter for closed fracture from V24 HCC 167
S02.631B Fracture of coronoid process of right mandible, initial encounter for open fracture from V24 HCC 167
S02.632A Fracture of coronoid process of left mandible, initial encounter for closed fracture from V24 HCC 167
S02.632B Fracture of coronoid process of left mandible, initial encounter for open fracture from V24 HCC 167
S02.640A Fracture of ramus of mandible, unspecified side, initial encounter for closed fracture from V24 HCC 167
S02.640B Fracture of ramus of mandible, unspecified side, initial encounter for open fracture from V24 HCC 167
S02.641A Fracture of ramus of right mandible, initial encounter for closed fracture from V24 HCC 167
S02.641B Fracture of ramus of right mandible, initial encounter for open fracture from V24 HCC 167
S02.642A Fracture of ramus of left mandible, initial encounter for closed fracture from V24 HCC 167
S02.642B Fracture of ramus of left mandible, initial encounter for open fracture from V24 HCC 167
S02.650A Fracture of angle of mandible, unspecified side, initial encounter for closed fracture from V24 HCC 167
S02.650B Fracture of angle of mandible, unspecified side, initial encounter for open fracture from V24 HCC 167
S02.651A Fracture of angle of right mandible, initial encounter for closed fracture from V24 HCC 167
S02.651B Fracture of angle of right mandible, initial encounter for open fracture from V24 HCC 167
S02.652A Fracture of angle of left mandible, initial encounter for closed fracture from V24 HCC 167
S02.652B Fracture of angle of left mandible, initial encounter for open fracture from V24 HCC 167
S02.66XA Fracture of symphysis of mandible, initial encounter for closed fracture from V24 HCC 167
S02.66XB Fracture of symphysis of mandible, initial encounter for open fracture from V24 HCC 167
S02.670A Fracture of alveolus of mandible, unspecified side, initial encounter for closed fracture from V24 HCC 167
S02.670B Fracture of alveolus of mandible, unspecified side, initial encounter for open fracture from V24 HCC 167
S02.671A Fracture of alveolus of right mandible, initial encounter for closed fracture from V24 HCC 167
S02.671B Fracture of alveolus of right mandible, initial encounter for open fracture from V24 HCC 167
S02.672A Fracture of alveolus of left mandible, initial encounter for closed fracture from V24 HCC 167
S02.672B Fracture of alveolus of left mandible, initial encounter for open fracture from V24 HCC 167
S02.69XA Fracture of mandible of other specified site, initial encounter for closed fracture from V24 HCC 167
S02.69XB Fracture of mandible of other specified site, initial encounter for open fracture from V24 HCC 167
S02.80XA Fracture of other specified skull and facial bones, unspecified side, initial encounter for closed fracture from V24 HCC 167
S02.80XB Fracture of other specified skull and facial bones, unspecified side, initial encounter for open fracture from V24 HCC 167
S02.81XA Fracture of other specified skull and facial bones, right side, initial encounter for closed fracture from V24 HCC 167
S02.81XB Fracture of other specified skull and facial bones, right side, initial encounter for open fracture from V24 HCC 167
S02.82XA Fracture of other specified skull and facial bones, left side, initial encounter for closed fracture from V24 HCC 167
S02.82XB Fracture of other specified skull and facial bones, left side, initial encounter for open fracture from V24 HCC 167
S02.831A Fracture of medial orbital wall, right side, initial encounter for closed fracture from V24 HCC 167
S02.831B Fracture of medial orbital wall, right side, initial encounter for open fracture from V24 HCC 167
S02.832A Fracture of medial orbital wall, left side, initial encounter for closed fracture from V24 HCC 167
S02.832B Fracture of medial orbital wall, left side, initial encounter for open fracture from V24 HCC 167
S02.839A Fracture of medial orbital wall, unspecified side, initial encounter for closed fracture from V24 HCC 167
S02.839B Fracture of medial orbital wall, unspecified side, initial encounter for open fracture from V24 HCC 167
S02.841A Fracture of lateral orbital wall, right side, initial encounter for closed fracture from V24 HCC 167
S02.841B Fracture of lateral orbital wall, right side, initial encounter for open fracture from V24 HCC 167
S02.842A Fracture of lateral orbital wall, left side, initial encounter for closed fracture from V24 HCC 167
S02.842B Fracture of lateral orbital wall, left side, initial encounter for open fracture from V24 HCC 167
S02.849A Fracture of lateral orbital wall, unspecified side, initial encounter for closed fracture from V24 HCC 167
S02.849B Fracture of lateral orbital wall, unspecified side, initial encounter for open fracture from V24 HCC 167
S02.85XA Fracture of orbit, unspecified, initial encounter for closed fracture from V24 HCC 167
S02.85XB Fracture of orbit, unspecified, initial encounter for open fracture from V24 HCC 167
S02.91XA Unspecified fracture of skull, initial encounter for closed fracture from V24 HCC 167
S02.91XB Unspecified fracture of skull, initial encounter for open fracture from V24 HCC 167
S02.92XA Unspecified fracture of facial bones, initial encounter for closed fracture from V24 HCC 167
S02.92XB Unspecified fracture of facial bones, initial encounter for open fracture from V24 HCC 167
S06.1X0A Traumatic cerebral edema without loss of consciousness, initial encounter from V24 HCC 167
S06.1XAA Traumatic cerebral edema with loss of consciousness status unknown, initial encounter from V24 HCC 167
S06.2X0A Diffuse traumatic brain injury without loss of consciousness, initial encounter from V24 HCC 167
S06.2XAA Diffuse traumatic brain injury with loss of consciousness status unknown, initial encounter from V24 HCC 167
S06.300A Unspecified focal traumatic brain injury without loss of consciousness, initial encounter from V24 HCC 167
S06.30AA Unspecified focal traumatic brain injury with loss of consciousness status unknown, initial encounter from V24 HCC 167
S06.310A Contusion and laceration of right cerebrum without loss of consciousness, initial encounter from V24 HCC 167
S06.31AA Contusion and laceration of right cerebrum with loss of consciousness status unknown, initial encounter from V24 HCC 167
S06.320A Contusion and laceration of left cerebrum without loss of consciousness, initial encounter from V24 HCC 167
S06.32AA Contusion and laceration of left cerebrum with loss of consciousness status unknown, initial encounter from V24 HCC 167
S06.330A Contusion and laceration of cerebrum, unspecified, without loss of consciousness, initial encounter from V24 HCC 167
S06.33AA Contusion and laceration of cerebrum, unspecified, with loss of consciousness status unknown, initial encounter from V24 HCC 167
S06.340A Traumatic hemorrhage of right cerebrum without loss of consciousness, initial encounter from V24 HCC 167
S06.34AA Traumatic hemorrhage of right cerebrum with loss of consciousness status unknown, initial encounter from V24 HCC 167
S06.350A Traumatic hemorrhage of left cerebrum without loss of consciousness, initial encounter from V24 HCC 167
S06.35AA Traumatic hemorrhage of left cerebrum with loss of consciousness status unknown, initial encounter from V24 HCC 167
S06.360A Traumatic hemorrhage of cerebrum, unspecified, without loss of consciousness, initial encounter from V24 HCC 167
S06.36AA Traumatic hemorrhage of cerebrum, unspecified, with loss of consciousness status unknown, initial encounter from V24 HCC 167
S06.370A Contusion, laceration, and hemorrhage of cerebellum without loss of consciousness, initial encounter from V24 HCC 167
S06.37AA Contusion, laceration, and hemorrhage of cerebellum with loss of consciousness status unknown, initial encounter from V24 HCC 167
S06.380A Contusion, laceration, and hemorrhage of brainstem without loss of consciousness, initial encounter from V24 HCC 167
S06.38AA Contusion, laceration, and hemorrhage of brainstem with loss of consciousness status unknown, initial encounter from V24 HCC 167
S06.4X0A Epidural hemorrhage without loss of consciousness, initial encounter from V24 HCC 167
S06.4XAA Epidural hemorrhage with loss of consciousness status unknown, initial encounter from V24 HCC 167
S06.5X0A Traumatic subdural hemorrhage without loss of consciousness, initial encounter from V24 HCC 167
S06.5XAA Traumatic subdural hemorrhage with loss of consciousness status unknown, initial encounter from V24 HCC 167
S06.6X0A Traumatic subarachnoid hemorrhage without loss of consciousness, initial encounter from V24 HCC 167
S06.6XAA Traumatic subarachnoid hemorrhage with loss of consciousness status unknown, initial encounter from V24 HCC 167
S06.810A Injury of right internal carotid artery, intracranial portion, not elsewhere classified without loss of consciousness, initial encounter from V24 HCC 167
S06.81AA Injury of right internal carotid artery, intracranial portion, not elsewhere classified with loss of consciousness status unknown, initial encounter from V24 HCC 167
S06.820A Injury of left internal carotid artery, intracranial portion, not elsewhere classified without loss of consciousness, initial encounter from V24 HCC 167
S06.82AA Injury of left internal carotid artery, intracranial portion, not elsewhere classified with loss of consciousness status unknown, initial encounter from V24 HCC 167
S06.890A Other specified intracranial injury without loss of consciousness, initial encounter from V24 HCC 167
S06.89AA Other specified intracranial injury with loss of consciousness status unknown, initial encounter from V24 HCC 167
S06.8A0A Primary blast injury of brain, not elsewhere classified without loss of consciousness, initial encounter from V24 HCC 167
S06.8AAA Primary blast injury of brain, not elsewhere classified with loss of consciousness status unknown, initial encounter from V24 HCC 167
S06.9X0A Unspecified intracranial injury without loss of consciousness, initial encounter from V24 HCC 167
S06.9XAA Unspecified intracranial injury with loss of consciousness status unknown, initial encounter from V24 HCC 167
S06.A0XA Traumatic brain compression without herniation, initial encounter from V24 HCC 167
S06.A1XA Traumatic brain compression with herniation, initial encounter from V24 HCC 167

Every code above carries the full HCC 399 weight when documented and reported on a Medicare Advantage encounter. The code link opens its full page with the complete risk adjustment card.

Questions About HCC 399

What is HCC 399 in the CMS-HCC model?

HCC 399 is CMS-HCC Category 399 (Major Head Injury without Loss of Consciousness) in the V28 risk adjustment model. It covers 189 ICD-10-CM diagnosis codes that raise a Medicare Advantage beneficiary's risk score when documented.

What is the RAF weight for HCC 399?

For payment year 2026, HCC 399 adds 0.199 to the RAF score of a community, non-dual, aged beneficiary. The published weights range from 0.052 to 0.349 across the seven payment segments shown above.

Which categories supersede HCC 399?

HCC 397 (Major Head Injury with Loss of Consciousness > 1 Hour) and HCC 398 (Major Head Injury with Loss of Consciousness < 1 Hour or Unspecified) sit above HCC 399 in the hierarchy: when a beneficiary has diagnoses in both, only the more severe category is paid.

Related References

All HCC Categories HCC 397 Codes HCC 398 Codes V24 to V28: What Changed ICD-10-CM Code Lookup

Source: Centers for Medicare & Medicaid Services, Payment Year 2026 risk adjustment mapping and model software releases (CMS-HCC V28), applied to the FY 2026 ICD-10-CM code set. ICD List is not affiliated with CMS.