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P04.13

Billable

Newborn affected by maternal use of anticonvulsants

Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)

Is P04.13 an HCC code?

Yes. P04.13 maps to Drug Use Disorder/Substance Use Disorder, Moderate/Severe under the CMS-HCC V28 risk adjustment model.

HCC Category Mapping

V28HCC 137Drug Use Disorder/Substance Use Disorder, Moderate/Severe
0.358

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 P04.13

For P04.13to 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 P04.13 during that encounter — not just copy-forwarded from a problem list.

What This Code Means

P04.13 is the ICD-10-CM diagnosis code for newborn affected by maternal use of anticonvulsants. The newborn was exposed to seizure-preventing medications taken by the mother during pregnancy. P04.13 sits in the ICD-10-CM chapter for certain conditions originating in the perinatal period (p00-p96), within the section covering newborn affected by maternal factors and by complications of pregnancy, labor, and delivery (p00-p04).

Under the CMS-HCC V28 risk adjustment model, P04.13 maps to Drug Use Disorder/Substance Use Disorder, Moderate/Severe (HCC 137) with a community, non-dual, aged base RAF weight of 0.358. P04.13 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.

Document which anticonvulsant(s) the mother used (e.g., phenytoin, valproic acid, phenobarbital). Because P04.13 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 P04.13 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

  • Document which anticonvulsant(s) the mother used (e.g., phenytoin, valproic acid, phenobarbital)
  • Monitor newborn for potential withdrawal symptoms or fetal anticonvulsant syndrome

Clinical Significance

Maternal anticonvulsant use during pregnancy can cause specific teratogenic effects including neural tube defects, cardiac malformations, and characteristic facial features in newborns. These infants require systematic evaluation for anticonvulsant embryopathy and long-term developmental monitoring.

Documentation Requirements

  • Documentation of maternal anticonvulsant medication use
  • Specific anticonvulsant agents taken during pregnancy
  • Dosage and duration of maternal treatment
  • Clinical features suggestive of anticonvulsant effects
  • Congenital anomaly screening results
  • Growth and developmental assessments
  • Coagulation studies if vitamin K deficiency suspected

Commonly Confused Codes

  • P04.18 — Newborn affected by other maternal medication
  • Q00.0 — Anencephaly (neural tube defect without drug cause documented)
  • P04.17 — Newborn affected by maternal use of sedative-hypnotics
  • P96.1 — Neonatal withdrawal symptoms from maternal drug use

Code Hierarchy

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