2027 ICD-10-CM Diagnosis Code R56.9Unspecified convulsions
R56.9 is a billable ICD-10-CM diagnosis code for unspecified convulsions. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 100 through 101, 791, 793. As a symptom code, it should not be used as a principal diagnosis once a related definitive diagnosis has been established. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Epilepsy; convulsions.
For Medicare Advantage risk adjustment, R56.9 maps to CMS-HCC Category 201 (Seizure Disorders and Convulsions) under the V28 model, adding a risk factor of about 0.245 for a community, non-dual, aged beneficiary in payment year 2027.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
R56.9 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.
Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Acute repetitive seizure
- Blood magnesium below reference range
- Blood magnesium outside reference range
- Central convulsion
- Central nervous system dysfunction in newborn
- Cortical blindness
- Daily seizures
- Disorder of beta and omega amino acid metabolism
- Disorder of gamma aminobutyric acid metabolism
- Disorder of lysine and hydroxylysine metabolism
- Early-onset seizures, distal limb anomalies, facial dysmorphism, global developmental delay syndrome
- EEG abnormality with seizure
- Emergency epilepsy treatment since last appointment
- Epilepsy monitoring status
- Epileptic cry
- Fall due to seizure
- Familial psoriasis
- Folinic acid responsive developmental and epileptic encephalopathy
- Genetic syndromic childhood obesity
- Global developmental delay, neuro-ophthalmological abnormalities, seizures, intellectual disability syndrome
- GNAO1-related developmental delay, seizures, movement disorder spectrum
- Intellectual disability, seizures, abnormal gait, facial dysmorphism syndrome
- Intellectual disability, seizures, hypotonia, ophthalmologic, skeletal anomalies syndrome
- Intellectual disability, seizures, macrocephaly, obesity syndrome
- IRF2BPL-related regressive neurodevelopmental disorder, dystonia, seizures syndrome
- Left ventricular myocardial noncompaction cardiomyopathy
- Lethal left ventricular non-compaction, seizures, hypotonia, cataract, developmental delay syndrome
- Lowered convulsive threshold
- Many seizures a day
- Microcephaly, seizure, intellectual disability, heart disease syndrome
- Neurodevelopmental delay, seizures, ophthalmic anomalies, osteopenia, cerebellar atrophy syndrome
- Osteogenesis imperfecta, retinopathy, seizures, intellectual disability syndrome
- Post-ictal state
- Postseizure headache
- Primary hyperaldosteronism, seizures, neurological abnormalities syndrome
- Primary hypomagnesemia, generalized seizures, intellectual disability, obesity syndrome
- Progressive microcephaly, seizures, cortical blindness, developmental delay syndrome
- Progressive microcephaly, seizures, cortical blindness, developmental delay with combined immunodeficiency due to DIAPH1 mutation
- Pyridoxine-dependent developmental and epileptic encephalopathy
- Raised convulsive threshold
- Recurrent encephalopathy
- Recurrent seizure
- Seizure
- Seizure disorder
- Seizures and intellectual disability due to hydroxylysinuria
- Tetanic convulsion
- Traumatic injury due to seizure
- Ventricular myocardial noncompaction cardiomyopathy
- X-linked intellectual disability with seizure and psoriasis syndrome
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to R56.9: its own notes plus those printed at R56 and Chapter 18. A note printed at a category, block or chapter applies to every code under it.
Applicable To
Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.
- Convulsion disorder
- Fit NOS
- Recurrent convulsions
- Seizure(s) (convulsive) NOS
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
Notes
General instructions on how these codes are used.
- 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.
- 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.
- The conditions and signs or symptoms included in categories R00-R94 consist of:
- (a) cases for which no more specific diagnosis can be made even after all the facts bearing on the case have been investigated;
- (b) signs or symptoms existing at the time of initial encounter that proved to be transient and whose causes could not be determined;
- (c) provisional diagnosis in a patient who failed to return for further investigation or care;
- (d) cases referred elsewhere for investigation or treatment before the diagnosis was made;
- (e) cases in which a more precise diagnosis was not available for any other reason;
- (f) certain symptoms, for which supplementary information is provided, that represent important problems in medical care in their own right.
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name R56.9, its category, or a range that includes it.
Excludes1 3
These codes carry an Excludes1 note naming R56.9: they are not reported together with it, unless the two conditions are unrelated.
Code Also 5
These codes say R56.9 may also be needed to fully describe the condition. The note gives no sequencing direction.
- E20.810 Autosomal dominant hypocalcemiaseizure disorder (G40.-, R56.9)
- G04.8 Other encephalitis, myelitis and encephalomyelitisany associated seizure (G40.-, R56.9)
- G43.1 Migraine with auraany associated seizure (G40.-, R56.9)
- G92.0 Immune effector cell-associated neurotoxicity syndromeunspecified convulsions (R56.9)
- I16.1 Hypertensive emergencyseizure (R56.9)
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Convulsions (idiopathic) See Also: Seizure(s); R56.9
recurrent R56.9
Disorder (of) See Also: Disease;
paroxysmal, mixed R56.9
Fit R56.9
Seizure (s) See Also: Convulsions; R56.9
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Seizures
clinical or subclinical disturbances of cortical function due to a sudden, abnormal, excessive, and disorganized discharge of brain cells. clinical manifestations include abnormal motor, sensory and psychic phenomena. recurrent seizures are usually referred to as epilepsy or seizure disorder.
Patient EducationClinical
Seizures
Seizures are symptoms of a brain problem. They happen because of sudden, abnormal electrical activity in the brain. When people think of seizures, they often think of convulsions in which a person's body shakes rapidly and uncontrollably. Not all seizures cause convulsions. There are many types of seizures and some have mild symptoms.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert R56.9 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About R56.9Overview
What is the ICD-10 code for unspecified convulsions?
The ICD-10-CM code for unspecified convulsions is R56.9 (sometimes written as R569). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is R56.9 (Convulsions, not elsewhere classified) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report unspecified convulsions on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does R56.9 group to?
When unspecified convulsions is the principal diagnosis on an inpatient stay, it groups to MS-DRG 793, 791, 100, 101, with relative weights from 0.8952 to 4.2192 depending on complications. Higher weights mean higher Medicare reimbursement.
Can R56.9 be a principal diagnosis?
Use it with care. This is a symptom code, so once a definitive diagnosis explaining the unspecified convulsions is established, that condition takes the principal position instead.
Can R56.9 be reported with F44.5?
Not as a rule. The Excludes1 note at R56, which applies to R56.9, lists "dissociative convulsions and seizures (F44.5)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
What HCC is R56.9?
R56.9 (unspecified convulsions) maps to CMS-HCC Category 201 (Seizure Disorders and Convulsions), commonly written as HCC 201, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 79 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. It does not map to any RxHCC in the Part D prescription drug model.
Does R56.9 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, R56.9 adds a risk adjustment factor of about 0.245 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.131 to 0.245 depending on the payment segment). HCC 201 sits at the top of its hierarchy, so no other condition category supersedes it. See the full factor table on the HCC 201 category page.
