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HCC 397: Major Head Injury with Loss of Consciousness > 1 Hour

HCC 397, Major Head Injury with Loss of Consciousness > 1 Hour, is one of the 115 payment categories in the CMS-HCC V28 model. 76 ICD-10-CM codes map to it in the payment year 2027 mapping, and a documented diagnosis in the category adds a relative factor of 0.199 to the risk score of a community, non-dual, aged beneficiary (0.150 disabled, 0.085 institutional). It sits at the top of its hierarchy, so no other category overrides it and it in turn overrides HCC 202, HCC 398, HCC 399.

QuickIntell editorial content · Legacy registry date · Review not verified

Data effective
Data currency: ICD-10-CM to HCC mapping PY2027 initial (effective dates of service 2026, payment year 2027); CMS-HCC V28 model software V2826.115.T2 (effective payment year 2027). Next CMS release: PY2027 midyear final mapping (spring 2027) and PY2028 proposed model (February 2027).
Mapped ICD-10-CM codes
76
Factor, community non-dual aged
0.199
Factor, institutional
0.085
Hierarchy
Top of hierarchy
Disease group
Injury

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.

CMS-HCC V28 relative factors for HCC 397 by model segment
SegmentModel codeRelative factor
Community, non-dual, agedCNA_HCC3970.199
Community, non-dual, disabledCND_HCC3970.150
Community, full-benefit dual, agedCFA_HCC3970.349
Community, full-benefit dual, disabledCFD_HCC3970.190
Community, partial-benefit dual, agedCPA_HCC3970.128
Community, partial-benefit dual, disabledCPD_HCC3970.052
Long-term institutionalINS_HCC3970.085

Hierarchy

Hierarchical condition categories pay only the most severe manifestation of a disease. HCC 397 is the most severe category in its hierarchy. When HCC 397 is present it drops HCC 202 (Coma, Brain Compression/Anoxic Damage), HCC 398 (Major Head Injury with Loss of Consciousness < 1 Hour or Unspecified), HCC 399 (Major Head Injury without Loss of Consciousness), 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 397

76 codes map to this category in the PY2027 initial mapping. 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 codes mapped to HCC 397 in the CMS PY2027 initial mapping
ICD-10-CMDescription
S061X3ATraumatic cerebral edema with loss of consciousness of 1 hour to 5 hours 59 minutes, initial encounter
S061X4ATraumatic cerebral edema with loss of consciousness of 6 hours to 24 hours, initial encounter
S061X5ATraumatic cerebral edema with loss of consciousness greater than 24 hours with return to pre-existing conscious level, initial encounter
S061X6ATraumatic cerebral edema with loss of consciousness greater than 24 hours without return to pre-existing conscious level with patient surviving, initial encounter
S062X3ADiffuse traumatic brain injury with loss of consciousness of 1 hour to 5 hours 59 minutes, initial encounter
S062X4ADiffuse traumatic brain injury with loss of consciousness of 6 hours to 24 hours, initial encounter
S062X5ADiffuse traumatic brain injury with loss of consciousness greater than 24 hours with return to pre-existing conscious levels, initial encounter
S062X6ADiffuse traumatic brain injury with loss of consciousness greater than 24 hours without return to pre-existing conscious level with patient surviving, initial encounter
S06303AUnspecified focal traumatic brain injury with loss of consciousness of 1 hour to 5 hours 59 minutes, initial encounter
S06304AUnspecified focal traumatic brain injury with loss of consciousness of 6 hours to 24 hours, initial encounter
S06305AUnspecified focal traumatic brain injury with loss of consciousness greater than 24 hours with return to pre-existing conscious level, initial encounter
S06306AUnspecified focal traumatic brain injury with loss of consciousness greater than 24 hours without return to pre-existing conscious level with patient surviving, initial encounter
S06313AContusion and laceration of right cerebrum with loss of consciousness of 1 hour to 5 hours 59 minutes, initial encounter
S06314AContusion and laceration of right cerebrum with loss of consciousness of 6 hours to 24 hours, initial encounter
S06315AContusion and laceration of right cerebrum with loss of consciousness greater than 24 hours with return to pre-existing conscious level, initial encounter
S06316AContusion and laceration of right cerebrum with loss of consciousness greater than 24 hours without return to pre-existing conscious level with patient surviving, initial encounter
S06323AContusion and laceration of left cerebrum with loss of consciousness of 1 hour to 5 hours 59 minutes, initial encounter
S06324AContusion and laceration of left cerebrum with loss of consciousness of 6 hours to 24 hours, initial encounter
S06325AContusion and laceration of left cerebrum with loss of consciousness greater than 24 hours with return to pre-existing conscious level, initial encounter
S06326AContusion and laceration of left cerebrum with loss of consciousness greater than 24 hours without return to pre-existing conscious level with patient surviving, initial encounter
S06333AContusion and laceration of cerebrum, unspecified, with loss of consciousness of 1 hour to 5 hours 59 minutes, initial encounter
S06334AContusion and laceration of cerebrum, unspecified, with loss of consciousness of 6 hours to 24 hours, initial encounter
S06335AContusion and laceration of cerebrum, unspecified, with loss of consciousness greater than 24 hours with return to pre-existing conscious level, initial encounter
S06336AContusion and laceration of cerebrum, unspecified, with loss of consciousness greater than 24 hours without return to pre-existing conscious level with patient surviving, initial encounter
S06343ATraumatic hemorrhage of right cerebrum with loss of consciousness of 1 hours to 5 hours 59 minutes, initial encounter
S06344ATraumatic hemorrhage of right cerebrum with loss of consciousness of 6 hours to 24 hours, initial encounter
S06345ATraumatic hemorrhage of right cerebrum with loss of consciousness greater than 24 hours with return to pre-existing conscious level, initial encounter
S06346ATraumatic hemorrhage of right cerebrum with loss of consciousness greater than 24 hours without return to pre-existing conscious level with patient surviving, initial encounter
S06353ATraumatic hemorrhage of left cerebrum with loss of consciousness of 1 hours to 5 hours 59 minutes, initial encounter
S06354ATraumatic hemorrhage of left cerebrum with loss of consciousness of 6 hours to 24 hours, initial encounter
S06355ATraumatic hemorrhage of left cerebrum with loss of consciousness greater than 24 hours with return to pre-existing conscious level, initial encounter
S06356ATraumatic hemorrhage of left cerebrum with loss of consciousness greater than 24 hours without return to pre-existing conscious level with patient surviving, initial encounter
S06363ATraumatic hemorrhage of cerebrum, unspecified, with loss of consciousness of 1 hours to 5 hours 59 minutes, initial encounter
S06364ATraumatic hemorrhage of cerebrum, unspecified, with loss of consciousness of 6 hours to 24 hours, initial encounter
S06365ATraumatic hemorrhage of cerebrum, unspecified, with loss of consciousness greater than 24 hours with return to pre-existing conscious level, initial encounter
S06366ATraumatic hemorrhage of cerebrum, unspecified, with loss of consciousness greater than 24 hours without return to pre-existing conscious level with patient surviving, initial encounter
S06373AContusion, laceration, and hemorrhage of cerebellum with loss of consciousness of 1 hour to 5 hours 59 minutes, initial encounter
S06374AContusion, laceration, and hemorrhage of cerebellum with loss of consciousness of 6 hours to 24 hours, initial encounter
S06375AContusion, laceration, and hemorrhage of cerebellum with loss of consciousness greater than 24 hours with return to pre-existing conscious level, initial encounter
S06376AContusion, laceration, and hemorrhage of cerebellum with loss of consciousness greater than 24 hours without return to pre-existing conscious level with patient surviving, initial encounter
S06383AContusion, laceration, and hemorrhage of brainstem with loss of consciousness of 1 hour to 5 hours 59 minutes, initial encounter
S06384AContusion, laceration, and hemorrhage of brainstem with loss of consciousness of 6 hours to 24 hours, initial encounter
S06385AContusion, laceration, and hemorrhage of brainstem with loss of consciousness greater than 24 hours with return to pre-existing conscious level, initial encounter
S06386AContusion, laceration, and hemorrhage of brainstem with loss of consciousness greater than 24 hours without return to pre-existing conscious level with patient surviving, initial encounter
S064X3AEpidural hemorrhage with loss of consciousness of 1 hour to 5 hours 59 minutes, initial encounter
S064X4AEpidural hemorrhage with loss of consciousness of 6 hours to 24 hours, initial encounter
S064X5AEpidural hemorrhage with loss of consciousness greater than 24 hours with return to pre-existing conscious level, initial encounter
S064X6AEpidural hemorrhage with loss of consciousness greater than 24 hours without return to pre-existing conscious level with patient surviving, initial encounter
S065X3ATraumatic subdural hemorrhage with loss of consciousness of 1 hour to 5 hours 59 minutes, initial encounter
S065X4ATraumatic subdural hemorrhage with loss of consciousness of 6 hours to 24 hours, initial encounter
S065X5ATraumatic subdural hemorrhage with loss of consciousness greater than 24 hours with return to pre-existing conscious level, initial encounter
S065X6ATraumatic subdural hemorrhage with loss of consciousness greater than 24 hours without return to pre-existing conscious level with patient surviving, initial encounter
S066X3ATraumatic subarachnoid hemorrhage with loss of consciousness of 1 hour to 5 hours 59 minutes, initial encounter
S066X4ATraumatic subarachnoid hemorrhage with loss of consciousness of 6 hours to 24 hours, initial encounter
S066X5ATraumatic subarachnoid hemorrhage with loss of consciousness greater than 24 hours with return to pre-existing conscious level, initial encounter
S066X6ATraumatic subarachnoid hemorrhage with loss of consciousness greater than 24 hours without return to pre-existing conscious level with patient surviving, initial encounter
S06813AInjury of right internal carotid artery, intracranial portion, not elsewhere classified with loss of consciousness of 1 hour to 5 hours 59 minutes, initial encounter
S06814AInjury of right internal carotid artery, intracranial portion, not elsewhere classified with loss of consciousness of 6 hours to 24 hours, initial encounter
S06815AInjury of right internal carotid artery, intracranial portion, not elsewhere classified with loss of consciousness greater than 24 hours with return to pre-existing conscious level, initial encounter
S06816AInjury of right internal carotid artery, intracranial portion, not elsewhere classified with loss of consciousness greater than 24 hours without return to pre-existing conscious level with patient surviving, initial encounter
S06823AInjury of left internal carotid artery, intracranial portion, not elsewhere classified with loss of consciousness of 1 hour to 5 hours 59 minutes, initial encounter
S06824AInjury of left internal carotid artery, intracranial portion, not elsewhere classified with loss of consciousness of 6 hours to 24 hours, initial encounter
S06825AInjury of left internal carotid artery, intracranial portion, not elsewhere classified with loss of consciousness greater than 24 hours with return to pre-existing conscious level, initial encounter
S06826AInjury of left internal carotid artery, intracranial portion, not elsewhere classified with loss of consciousness greater than 24 hours without return to pre-existing conscious level with patient surviving, initial encounter
S06893AOther specified intracranial injury with loss of consciousness of 1 hour to 5 hours 59 minutes, initial encounter
S06894AOther specified intracranial injury with loss of consciousness of 6 hours to 24 hours, initial encounter
S06895AOther specified intracranial injury with loss of consciousness greater than 24 hours with return to pre-existing conscious level, initial encounter
S06896AOther specified intracranial injury with loss of consciousness greater than 24 hours without return to pre-existing conscious level with patient surviving, initial encounter
S068A3APrimary blast injury of brain, not elsewhere classified with loss of consciousness of 1 hour to 5 hours 59 minutes, initial encounter
S068A4APrimary blast injury of brain, not elsewhere classified with loss of consciousness of 6 hours to 24 hours, initial encounter
S068A5APrimary blast injury of brain, not elsewhere classified with loss of consciousness greater than 24 hours with return to pre-existing conscious level, initial encounter
S068A6APrimary blast injury of brain, not elsewhere classified with loss of consciousness greater than 24 hours without return to pre-existing conscious level with patient surviving, initial encounter
S069X3AUnspecified intracranial injury with loss of consciousness of 1 hour to 5 hours 59 minutes, initial encounter
S069X4AUnspecified intracranial injury with loss of consciousness of 6 hours to 24 hours, initial encounter
S069X5AUnspecified intracranial injury with loss of consciousness greater than 24 hours with return to pre-existing conscious level, initial encounter
S069X6AUnspecified intracranial injury with loss of consciousness greater than 24 hours without return to pre-existing conscious level with patient surviving, 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 categories that the HCC 397 codes mapped to
V22 HCCCodes
16676

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 397?

76 ICD-10-CM codes map to HCC 397 in the CMS PY2027 initial mapping, for example S061X3A Traumatic cerebral edema with loss of consciousness of 1 hour to 5 hours 59 minutes, initial encounter; S061X4A Traumatic cerebral edema with loss of consciousness of 6 hours to 24 hours, initial encounter; S061X5A Traumatic cerebral edema with loss of consciousness greater than 24 hours with return to pre-existing conscious level, initial encounter; S061X6A Traumatic cerebral edema with loss of consciousness greater than 24 hours without return to pre-existing conscious level with patient surviving, initial encounter. 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 397 add to a risk score?

The V28 relative factor for HCC 397 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 397 count together with related categories?

No. Within a hierarchy only the most severe category is paid. HCC 397 is the most severe category in its hierarchy, and it drops HCC 202, HCC 398, HCC 399 when it is present.

What has to be documented for HCC 397 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.

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.