FY2027 ICD-10-CM reference
R56.00: Simple febrile convulsions
By the HCC Buddy Coding Team
The official ICD-10-CM descriptor is Simple febrile convulsions. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
Billable code. Verified against the official FY2027 order file.
FY2027 Tabular instructions
Instructions below include applicable chapter, section and parent-code notes. Each note identifies where it appears in the official source.
Instructional note
This chapter includes symptoms, signs, abnormal results of clinical or other investigative procedures, and ill-defined conditions regarding which no diagnosis classifiable elsewhere is recorded.
Source: R00-R99 (chapter, inherited).
Instructional note
Signs and symptoms that point rather definitely to a given diagnosis have been assigned to a category in other chapters of the classification. In general, categories in this chapter include the less well-defined conditions and symptoms that, without the necessary study of the case to establish a final diagnosis, point perhaps equally to two or more diseases or to two or more systems of the body. Practically all categories in the chapter could be designated 'not otherwise specified', 'unknown etiology' or 'transient'. The Alphabetical Index should be consulted to determine which symptoms and signs are to be allocated here and which to other chapters. The residual subcategories, numbered .8, are generally provided for other relevant symptoms that cannot be allocated elsewhere in the classification.
Source: R00-R99 (chapter, inherited).
Instructional note
The conditions and signs or symptoms included in categories R00-R94 consist of:
Source: R00-R99 (chapter, inherited).
Instructional note
(a) cases for which no more specific diagnosis can be made even after all the facts bearing on the case have been investigated;
Source: R00-R99 (chapter, inherited).
Instructional note
(b) signs or symptoms existing at the time of initial encounter that proved to be transient and whose causes could not be determined;
Source: R00-R99 (chapter, inherited).
Instructional note
(c) provisional diagnosis in a patient who failed to return for further investigation or care;
Source: R00-R99 (chapter, inherited).
Instructional note
(d) cases referred elsewhere for investigation or treatment before the diagnosis was made;
Source: R00-R99 (chapter, inherited).
Instructional note
(e) cases in which a more precise diagnosis was not available for any other reason;
Source: R00-R99 (chapter, inherited).
Instructional note
(f) certain symptoms, for which supplementary information is provided, that represent important problems in medical care in their own right.
Source: R00-R99 (chapter, inherited).
Excludes2
abnormal findings on antenatal screening of mother (O28.-)
Source: R00-R99 (chapter, inherited).
Excludes2
certain conditions originating in the perinatal period (P04-P96)
Source: R00-R99 (chapter, inherited).
Excludes2
signs and symptoms classified in the body system chapters
Source: R00-R99 (chapter, inherited).
Excludes2
signs and symptoms of breast (N63, N64.5)
Source: R00-R99 (chapter, inherited).
Excludes1
dissociative convulsions and seizures (F44.5)
Source: R56 (category, inherited).
Excludes1
epileptic convulsions and seizures (G40.-)
Source: R56 (category, inherited).
Excludes1
newborn convulsions and seizures (P90)
Source: R56 (category, inherited).
Instructional note
Febrile convulsion NOS
Source: R56.00 (self, direct).
Instructional note
Febrile seizure NOS
Source: R56.00 (self, direct).
Compare the FY2027 additions, removals and billable-status changes
What does R56.00 mean in FY2027?
The official ICD-10-CM descriptor is Simple febrile convulsions. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
Is R56.00 billable in FY2027?
The FY2027 order file marks R56.00 as billable. Check the complete Tabular instructions and documentation before assigning it.
Does R56.00 map to an HCC?
In the CMS 2027 Initial ICD-10-CM Mappings (payment year 2027, 2026 dates of service), R56.00 maps to CMS-HCC V28 HCC 201 (Seizure Disorders and Convulsions). For 2027 dates of service, CMS has not yet published the payment year 2028 mappings. ESRD, RxHCC, PACE and HHS-HCC mappings are still pending verification for FY2027.
Source: CMS FY2027 ICD-10-CM order file. Read the FY2027 Official Guidelines.
Review the FY2026 April edition