R56.9 ICD-10-CM Code: Unspecified convulsions
Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.
Coding at a Glance
- Tabular directives
- 4 inclusion terms · 3 Excludes1
- Risk adjustment
- CMS-HCC V28: 1 category · CMS-HCC V22 category 79
Inpatient Payment Groups (MS-DRG)
Potential MS-DRG participation — not a DRG assignment.
MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v43, Appendix B.
- MS-DRG 100 — SEIZURES WITH MCC (MDC 01)
- MS-DRG 101 — SEIZURES WITHOUT MCC (MDC 01)
- MS-DRG 791 — PREMATURITY WITH MAJOR PROBLEMS (MDC 15)
- MS-DRG 793 — FULL TERM NEONATE WITH MAJOR PROBLEMS (MDC 15)
A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.
Risk Adjustment (CMS-HCC)
Payment categories this diagnosis maps to under CMS-HCC V28, payment year 2026.
- HCC 201 — Seizure Disorders and Convulsions
Other models: CMS-HCC V22 HCC 79
Risk scores depend on the enrollee's full accepted diagnosis set and segment; a category mapping alone does not determine payment.
Coding instructions
Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for R56.9 in the official ICD-10-CM tabular list, quoted as published.
Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2026Effective: October 1, 2025
Notes without a marker are published on R56.9 itself; “inherited from” names the category or block whose note applies here.
Inclusion Terms
Alternative terms the tabular list files under this code.
- Convulsion disorder
- Fit NOS
- Recurrent convulsions
- Seizure(s) (convulsive) NOS
Excludes1 — Not Coded Here
Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
- dissociative convulsions and seizures (F44.5) Compare R56.9 vs F44.5 →
- epileptic convulsions and seizures (G40.-) Compare R56.9 vs G40 →
- newborn convulsions and seizures (P90) Compare R56.9 vs P90 →
Source: inherited from R56
Coder workflow for R56.9
MedCoder structured workflow — derived from this code’s own official record
Before you code R56.9
- Check whether an established diagnosis that explains this sign or symptom is documented. If one is, review whether the documented diagnosis changes the coding pathway: a symptom that is integral to a confirmed diagnosis is not reported separately, while one not routinely associated with it may be. Signs and symptoms are reported when no definitive diagnosis is established (Guidelines I.B.4, I.B.5, I.B.6, I.C.18.b).
- Unspecified does not mean incorrect. When the record gives no greater specificity, R56.9 may be the appropriate code. Check the record for detail that supports a more specific sibling. An unspecified code is for records that do not provide the detail a more specific code needs; a query, not an assumption, is the route to specificity (Guidelines I.A.9.b, I.B.18).
See the relationships section · Guide: Other vs unspecified (NEC vs NOS) →
- Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with R56.9. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).
Choose the right path
- Is an established diagnosis that explains this sign or symptom documented?
Yes → Review whether the documented diagnosis changes the coding pathway: a symptom integral to it is not reported separately.
No → Continue — the sign or symptom code stands when no definitive diagnosis is established. - Does the record document the detail a more specific sibling code needs?
Yes → Review the specific siblings in this subcategory.
No → Continue — R56.9 is appropriate when the documentation goes no further. - Does the documentation support a condition named in R56.9’s Excludes1 note?
Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
No → Continue.
Consider R56.9. Then confirm the code is valid for the date of service in the Verify section.
Documentation check
- The provider’s diagnostic statement
- Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).
- Any detail beyond this code’s title
- What the record states that a more specific sibling code would capture — or its absence, which itself supports the unspecified code.
Official instructions as workflow
Excludes1 — check before selecting R56.9(3 notes)
Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with R56.9: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.
See the official tabular notes · Guidelines I.A.12.a
Coding decision scenarios
Pattern scenarios for this code’s structure — decision rules, not clinical cases
Documentation: The sign or symptom is documented, and the same record establishes a diagnosis that routinely includes it.
Coding question: Is R56.9 reported in addition to the diagnosis?
Path: Review the documented diagnosis and whether the classification treats this finding as integral to it.
Reason: Signs and symptoms integral to a confirmed diagnosis are not coded separately; those not routinely associated with it may be reported when present (Guidelines I.B.5, I.B.6, I.C.18.b).
Documentation: The provider documents the condition in the terms of this code’s title and records no further detail.
Coding question: Is a more specific sibling code supportable?
Path: Review the specific siblings in this subcategory and what each requires the record to state.
Reason: A more specific code needs documentation of the distinguishing element; without it the unspecified code is appropriate, and a provider query is the route to specificity (Guidelines I.A.9.b, I.B.18).
Documentation: Both the condition R56.9 describes and a condition named in its Excludes1 note are documented for the same encounter.
Coding question: Can both codes be reported?
Path: Review the Excludes1 note and the excluded code, and look for a provider statement on whether the two conditions are related.
Reason: Excludes1 means the two are not coded together; the exception is when the record shows the conditions are unrelated to each other (Guidelines I.A.12.a).
Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.
Code Overview
MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.
Indexed Clinical Terms (5)
Official source data — entries quoted as published, in the Index’s own lookup phrasing
Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.
Verify Before Coding
- No Medicare Code Editor or MS-DRG Definitions Manual restrictions apply to this code.
From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.
Relationships & Classification
MedCoder structured relationships — computed from published CMS and AHRQ datasets
Other codes that name R56.9 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.
Referenced by 2 Excludes1 notes: G40 — Epilepsy and recurrent seizures, G40.89 — Other seizures.
These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.
Referenced by 5 Code Also instructions across 3 chapters: E20.810 — Autosomal dominant hypocalcemia, G04.8 — Other encephalitis, myelitis and encephalomyelitis, G43.1 — Migraine with aura, G92.0 — Immune effector cell-associated neurotoxicity syndrome, I16.1 — Hypertensive emergency.
These codes suggest coding this condition alongside when both are present.
MS-DRG Grouper Relationships (FY2026)
Potential MS-DRG participation — not a DRG assignment.
FY2026 MS-DRG: not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity for that release.
Named in the grouper logic of 4 MS-DRGs: DRG 100 (MDC 01), DRG 101 (MDC 01), DRG 791 (MDC 15), DRG 793 (MDC 15).
From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.
Clinical classification (AHRQ CCSR):NVS009 — Epilepsy; convulsions (default).
Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.
Related Codes
Same CMS-HCC risk category (V28)
CMS maps these diagnoses to the same Hierarchical Condition Category (Seizure Disorders and Convulsions) for risk-adjusted payment.
G40.909 — Epilepsy, unspecified, not intractable, without status epilepticus, G40.911 — Epilepsy, unspecified, intractable, with status epilepticus, G40.919 — Epilepsy, unspecified, intractable, without status epilepticus, G40.A01 — Absence epileptic syndrome, not intractable, with status epilepticus, G40.A09 — Absence epileptic syndrome, not intractable, without status epilepticus, G40.A11 — Absence epileptic syndrome, intractable, with status epilepticus, G40.A19 — Absence epileptic syndrome, intractable, without status epilepticus, G40.B01 — Juvenile myoclonic epilepsy, not intractable, with status epilepticus, G40.B09 — Juvenile myoclonic epilepsy, not intractable, without status epilepticus, G40.B11 — Juvenile myoclonic epilepsy, intractable, with status epilepticus, G40.B19 — Juvenile myoclonic epilepsy, intractable, without status epilepticus, G40.C01 — Lafora progressive myoclonus epilepsy, not intractable, with status epilepticus, G40.C09 — Lafora progressive myoclonus epilepsy, not intractable, without status epilepticus, G40.C11 — Lafora progressive myoclonus epilepsy, intractable, with status epilepticus, G40.C19 — Lafora progressive myoclonus epilepsy, intractable, without status epilepticus, G93.45 — Developmental and epileptic encephalopathy, P90 — Convulsions of newborn, R56.00 — Simple febrile convulsions, R56.01 — Complex febrile convulsions, R56.1 — Post traumatic seizures, +43 more
Same clinical category (CCSR)
AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Epilepsy; convulsions).
G40.901 — Epilepsy, unspecified, not intractable, with status epilepticus, G40.909 — Epilepsy, unspecified, not intractable, without status epilepticus, G40.911 — Epilepsy, unspecified, intractable, with status epilepticus, G40.919 — Epilepsy, unspecified, intractable, without status epilepticus, G40.A01 — Absence epileptic syndrome, not intractable, with status epilepticus, G40.A09 — Absence epileptic syndrome, not intractable, without status epilepticus, G40.A11 — Absence epileptic syndrome, intractable, with status epilepticus, G40.A19 — Absence epileptic syndrome, intractable, without status epilepticus, G40.B01 — Juvenile myoclonic epilepsy, not intractable, with status epilepticus, G40.B09 — Juvenile myoclonic epilepsy, not intractable, without status epilepticus, G40.B11 — Juvenile myoclonic epilepsy, intractable, with status epilepticus, G40.B19 — Juvenile myoclonic epilepsy, intractable, without status epilepticus, G40.C01 — Lafora progressive myoclonus epilepsy, not intractable, with status epilepticus, G40.C09 — Lafora progressive myoclonus epilepsy, not intractable, without status epilepticus, G40.C11 — Lafora progressive myoclonus epilepsy, intractable, with status epilepticus, G40.C19 — Lafora progressive myoclonus epilepsy, intractable, without status epilepticus, G93.45 — Developmental and epileptic encephalopathy, R56.00 — Simple febrile convulsions, R56.01 — Complex febrile convulsions, R56.1 — Post traumatic seizures, +42 more
Same Index main term, other category
The ICD-10-CM Index to Diseases and Injuries files this code under the main terms “Fit”, “Convulsions”, “Seizure”; these codes share that main term but sit in a different category of the Tabular List.
G40.401 — Other generalized epilepsy and epileptic syndromes, not intractable, with status epilepticus (grand mal, not intractable, with status epilepticus), G40.409 — Other generalized epilepsy and epileptic syndromes, not intractable, without status epilepticus (grand mal), G40.411 — Other generalized epilepsy and epileptic syndromes, intractable, with status epilepticus (grand mal, intractable, with status epilepticus), G40.419 — Other generalized epilepsy and epileptic syndromes, intractable, without status epilepticus (grand mal, intractable), G40.89 — Other seizures (specified NEC), G40.901 — Epilepsy, unspecified, not intractable, with status epilepticus (febrile, with status epilepticus), G40.909 — Epilepsy, unspecified, not intractable, without status epilepticus (disorder), G40.911 — Epilepsy, unspecified, intractable, with status epilepticus (intractable, with status epilepticus), G40.919 — Epilepsy, unspecified, intractable, without status epilepticus (intractable), G40.A — Absence epileptic syndrome (absence), G40.A0 — Absence epileptic syndrome, not intractable (petit mal, not intractable), G40.A01 — Absence epileptic syndrome, not intractable, with status epilepticus (petit mal, not intractable, with status epilepticus), G40.A09 — Absence epileptic syndrome, not intractable, without status epilepticus (petit mal, not intractable, without status epilepticus), G40.A1 — Absence epileptic syndrome, intractable (petit mal, intractable), G40.A11 — Absence epileptic syndrome, intractable, with status epilepticus (petit mal, intractable, with status epilepticus), G40.A19 — Absence epileptic syndrome, intractable, without status epilepticus (petit mal, intractable, without status epilepticus), I67.82 — Cerebral ischemia (apoplectiform), P90 — Convulsions of newborn (newborn), R25.8 — Other abnormal involuntary movements (reflex), R55 — Syncope and collapse (fainting), +5 more
Lab tests where this diagnosis supports Medicare coverage (NCD)
Medicare's National Coverage Determination (NCD) program lists this diagnosis as medical justification for these lab tests.
Contextual Map
Every relationship of R56.9 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.
Run R56.9 with these 7 related codes in Claim Check
Hierarchy
- R00-R99 — Chapter 18: Symptoms, Signs and Abnormal Clinical and Laboratory Findings, Not Elsewhere Classified (R00-R99) (R00-R99)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- R50-R69 — General symptoms and signs[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
Referenced by Excludes1 notes
- G40 — Epilepsy and recurrent seizures[Excludes1]: “convulsions NOS (R56.9)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- G40.89 — Other seizures[Excludes1]: “seizure NOS (R56.9)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
Referenced by Code Also instructions
- E20.810 — Autosomal dominant hypocalcemia[Code Also]: “seizure disorder (G40.-, R56.9)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- G04.8 — Other encephalitis, myelitis and encephalomyelitis[Code Also]: “any associated seizure (G40.-, R56.9)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- G43.1 — Migraine with aura[Code Also]: “any associated seizure (G40.-, R56.9)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- G92.0 — Immune effector cell-associated neurotoxicity syndrome[Code Also]: “unspecified convulsions (R56.9)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- I16.1 — Hypertensive emergency[Code Also]: “seizure (R56.9)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
Clinical classification (CCSR)
- NVS009 — Epilepsy; convulsions[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)
Risk adjustment (CMS-HCC)
- HCC 201 — Seizure Disorders and Convulsions [CMS-HCC]— CMS-HCC V28 · 2026
MS-DRG Grouper
- DRG 100 — SEIZURES WITH MCC[MS-DRG]: “SEIZURES WITH MCC (MDC 01)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
- DRG 101 — SEIZURES WITHOUT MCC[MS-DRG]: “SEIZURES WITHOUT MCC (MDC 01)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
- DRG 791 — PREMATURITY WITH MAJOR PROBLEMS[MS-DRG]: “PREMATURITY WITH MAJOR PROBLEMS (MDC 15)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
- DRG 793 — FULL TERM NEONATE WITH MAJOR PROBLEMS[MS-DRG]: “FULL TERM NEONATE WITH MAJOR PROBLEMS (MDC 15)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
MDC crossing
- MDC 01 — Diseases and Disorders of the Nervous System[MDC crossing]: “Diseases and Disorders of the Nervous System — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 8,892 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026
- MDC 15 — Newborns and Other Neonates with Conditions Originating in Perinatal Period[MDC crossing]: “Newborns and Other Neonates with Conditions Originating in Perinatal Period — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs.”— CMS MS-DRG Definitions Manual · FY2026
Index entries
- Convulsions (idiopathic)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
- Convulsions (idiopathic), recurrent[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
- Disorder (of), paroxysmal, mixed[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
- Fit[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
- Seizure (s)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
Nearest codes
- R56 — Convulsions, not elsewhere classified[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- R56.0 — Febrile convulsions[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- R56.00 — Simple febrile convulsions[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- R56.01 — Complex febrile convulsions[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- R56.1 — Post traumatic seizures[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
Change history
- FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016
Sources for this page
Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.
- Code, title, tabular notes and index terms Official source data
- CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page
- Claim edits Official source data
- CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page
- Inpatient payment groups Official source data
- CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v43 Release, file and checksum · Publisher’s page
- Risk adjustment Official source data
- 2026 Mid-Year Final ICD-10 Mappings + Model Software (cms.gov/files/zip/2026-midyear-final-icd-10-mappings.zip, 2026-midyear-final-model-software.zip) — CMS-HCC V28, PY2026 mid-year final release Release, file and checksum · Publisher’s page
- Change history and date-of-service validity Official source data
- CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
- Comparisons, relationships and the contextual map MedCoder structured relationship
- Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
- Summary and FAQ answers MedCoder explanation
- Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.
Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates
Change history
- FY2016 — October 1, 2015In the code set at ICD-10-CM adoptionUnspecified convulsions
No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027 (effective October 1, 2026), and none are recorded for this code. Note changes are tracked from FY2027 only.
Nearest Codes in This Family
Official ICD-10-CM classifications closest to R56.9 in its code family, with their registry titles.