R56.1 ICD-10-CM Code: Post traumatic seizures
HCC Buddy Code Card
Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.
FY 2026 Apr update / Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99) / General symptoms and signs (R50-R69)
R56.1
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidancePost traumatic seizures
Seizures that develop as a result of a head injury or traumatic brain injury, occurring after the initial trauma.
Buddy Insight
Post-traumatic seizures occur following head trauma and indicate potential brain injury requiring neurological evaluation and monitoring.
CMS-HCC V28
MappedHCC 201
RAF 0.262
CMS-HCC V24
MappedHCC 79
RAF 0.244
ACA/HHS
00
RAF 0
ESRD/PACE
MappedHCC 79
RAF 0.0
RXHCC
00
RAF 0
Code Trumping
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Code Book Path
Inclusion Terms
OfficialICD-10-CM does not list inclusion terms for R56.1 in this effective period.
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for R56.1 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for R56.1 in this effective period.
Excludes 1
Official- post traumatic epilepsy (G40.-)
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for R56.1 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for R56.1 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for R56.1 in this effective period.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.
Is R56.1 an HCC code?
Yes. R56.1 maps to Seizure Disorders and Convulsions under the CMS-HCC V28 risk adjustment model (and Seizure Disorders and Convulsions under V24).
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 R56.1
For R56.1to 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 R56.1 during that encounter, not just copy-forwarded from a problem list.
What This Code Means
R56.1 is the ICD-10-CM diagnosis code for post traumatic seizures. Seizures that develop as a result of a head injury or traumatic brain injury, occurring after the initial trauma. R56.1 sits in the ICD-10-CM chapter for symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (r00-r99), within the section covering general symptoms and signs (r50-r69).
Under the CMS-HCC V28 risk adjustment model, R56.1 maps to Seizure Disorders and Convulsions (HCC 201) with a community, non-dual, aged base RAF weight of 0.262. Under the older V24 model, R56.1 mapped to the same category but with a base RAF weight of 0.244, V28 recalibrated weights across the entire model. 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.
Always code the associated head injury or trauma code in addition to this seizure code. Because R56.1 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 R56.1 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Always code the associated head injury or trauma code in addition to this seizure code
- •Document the timing of seizure onset relative to the traumatic event (immediate vs. delayed)
Clinical Significance
Post-traumatic seizures occur following head trauma and indicate potential brain injury requiring neurological evaluation and monitoring. These seizures may be early (within 7 days) or late (after 7 days) post-injury, with different implications for prognosis and risk of developing post-traumatic epilepsy requiring ongoing management.
Documentation Requirements
- ✓Documentation of seizure following head trauma
- ✓Timing of seizure relative to trauma (early vs late)
- ✓Type and severity of head injury
- ✓Neurological examination findings
- ✓Imaging results (CT or MRI brain)
- ✓EEG findings if performed
- ✓Antiepileptic medication initiated
- ✓Follow-up neurological care planning
Excludes 1, Do NOT code together
- post traumatic epilepsy (G40.-)