P91.5
BillableNeonatal coma
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is P91.5 an HCC code?
Yes. P91.5 maps to Coma, Brain Compression/Anoxic Damage under the CMS-HCC V28 risk adjustment model.
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.
MEAT Criteria for P91.5
For P91.5 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically — it has to be re-documented and supported each calendar year.
- MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
- EEvaluate: test results, medication response, or physical findings reviewed by the provider
- AAssess: explicit mention in the assessment or plan with acknowledgment of status
- TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis
Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed P91.5 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
P91.5 is the ICD-10-CM diagnosis code for neonatal coma. A state of unconsciousness in a newborn where the infant cannot be aroused and does not respond to external stimuli. P91.5 sits in the ICD-10-CM chapter for certain conditions originating in the perinatal period (p00-p96), within the section covering other disorders originating in the perinatal period (p90-p96).
Under the CMS-HCC V28 risk adjustment model, P91.5 maps to Coma, Brain Compression/Anoxic Damage (HCC 202) with a community, non-dual, aged base RAF weight of 0.000. P91.5 was not retained as a payment HCC under the older V24 model, so V28 introduced or recategorized it during the 2024–2026 phase-in. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.
This is a serious condition; ensure thorough documentation of the cause and any interventions performed. Because P91.5 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for P91.5 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This is a serious condition; ensure thorough documentation of the cause and any interventions performed
- •Code any underlying etiology separately, such as severe hypoxia, infection, or metabolic crisis
Clinical Significance
Neonatal coma represents the most severe form of altered consciousness in newborns, indicating critical brain dysfunction. This diagnosis carries extremely high morbidity and mortality risk, requiring immediate intensive care and aggressive investigation of underlying causes.
Documentation Requirements
- ✓Clear documentation of comatose state with inability to arouse
- ✓Glasgow Coma Scale or neonatal neurological scoring if available
- ✓Complete lack of response to external stimuli documented
- ✓Underlying etiology investigated (hypoxia, infection, trauma, metabolic)
- ✓Neuroimaging findings if obtained
- ✓EEG findings documenting brain activity patterns
- ✓Response to therapeutic interventions
- ✓Prognosis and family discussions documented