R56.00 ICD-10-CM Code: Simple febrile convulsions
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)
R56.00
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceSimple febrile convulsions
Brief seizures or convulsions in a child caused by high fever, without any underlying neurological disorder. These seizures typically stop when the fever is treated.
Buddy Insight
Simple febrile convulsions are brief seizures in children triggered by fever, typically lasting less than 15 minutes and not recurring within 24 hours.
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
Basket needed
Code Book Path
Inclusion Terms
Official- Febrile convulsion NOS
- Febrile seizure NOS
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for R56.00 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for R56.00 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for R56.00 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for R56.00 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for R56.00 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for R56.00 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 R56.00 an HCC code?
Yes. R56.00 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 R56.00
For R56.00to 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 R56.00 during that encounter, not just copy-forwarded from a problem list.
What This Code Means
R56.00 is the ICD-10-CM diagnosis code for simple febrile convulsions. Brief seizures or convulsions in a child caused by high fever, without any underlying neurological disorder. These seizures typically stop when the fever is treated. R56.00 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, R56.00 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, R56.00 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.
This code is specifically for febrile seizures in children without a history of epilepsy. Because R56.00 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 R56.00 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This code is specifically for febrile seizures in children without a history of epilepsy
- •Ensure the fever is documented and coded separately; if seizures occur without fever, use a different code
Clinical Significance
Simple febrile convulsions are brief seizures in children triggered by fever, typically lasting less than 15 minutes and not recurring within 24 hours. While generally benign, these episodes require evaluation to rule out serious infections and monitoring for potential development of epilepsy, with most children having normal neurological development.
Documentation Requirements
- ✓Documentation of seizure associated with fever
- ✓Age of child (typically 6 months to 5 years)
- ✓Duration of seizure (brief, <15 minutes)
- ✓Single episode in 24-hour period
- ✓Generalized tonic-clonic nature
- ✓Temperature recorded during episode
- ✓Neurological examination findings
- ✓Investigation for underlying infection