MS-DRG · FY 2026 v43.0
MS-DRG 101 – Seizures without MCC
A Medical DRG in MDC 01 (Diseases & Disorders of the Nervous System). Inpatient cases group to DRG 101 when the ICD-10-CM principal diagnosis is one of the 62 codes listed below and no secondary diagnosis on the MCC list is present. Its FY 2026 relative weight is 0.9026 with a geometric mean length of stay of 2.6 days.
Medical DRG – assigned by principal diagnosis✓ Official CMS v43.0 dataset
0.9026
Relative Weight
2.6
Geometric Mean LOS (days)
3.4
Arithmetic Mean LOS (days)
62
Principal Diagnosis Codes
Severity family
DRG 100with MCCWeight 1.9368 · GMLOS 4.3 daysDRG 101without MCCWeight 0.9026 · GMLOS 2.6 days
How a case is assigned to DRG 101
The grouper first assigns the case to MDC 01 from the principal diagnosis and finds no qualifying operating-room procedure (this is a Medical DRG; ICD-10-PCS codes do not drive assignment here), then applies the severity split from secondary diagnoses: with MCC → 100; without MCC → 101.
ICD-10-CM
Principal Diagnosis Codes 62 codes · 2 categories
62 of 62 shown
G40 Epilepsy and recurrent seizures58 codes
- G40.001 Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, not intractable, with status epilepticus
- G40.009 Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, not intractable, without status epilepticus
- G40.011 Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, intractable, with status epilepticus
- G40.019 Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, intractable, without status epilepticus
- G40.101 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, not intractable, with status epilepticus
- G40.109 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, not intractable, without status epilepticus
- G40.111 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, intractable, with status epilepticus
- G40.119 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, intractable, without status epilepticus
- G40.201 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, not intractable, with status epilepticus
- G40.209 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, not intractable, without status epilepticus
- G40.211 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, intractable, with status epilepticus
- G40.219 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, intractable, without status epilepticus
- G40.301 Generalized idiopathic epilepsy and epileptic syndromes, not intractable, with status epilepticus
- G40.309 Generalized idiopathic epilepsy and epileptic syndromes, not intractable, without status epilepticus
- G40.311 Generalized idiopathic epilepsy and epileptic syndromes, intractable, with status epilepticus
- G40.319 Generalized idiopathic epilepsy and epileptic syndromes, intractable, without status epilepticus
- G40.401 Other generalized epilepsy and epileptic syndromes, not intractable, with status epilepticus
- G40.409 Other generalized epilepsy and epileptic syndromes, not intractable, without status epilepticus
- G40.411 Other generalized epilepsy and epileptic syndromes, intractable, with status epilepticus
- G40.419 Other generalized epilepsy and epileptic syndromes, intractable, without status epilepticus
- G40.42 Cyclin-Dependent Kinase-Like 5 Deficiency Disorder
- G40.501 Epileptic seizures related to external causes, not intractable, with status epilepticus
- G40.509 Epileptic seizures related to external causes, not intractable, without status epilepticus
- G40.801 Other epilepsy, not intractable, with status epilepticus
- G40.802 Other epilepsy, not intractable, without status epilepticus
- G40.803 Other epilepsy, intractable, with status epilepticus
- G40.804 Other epilepsy, intractable, without status epilepticus
- G40.811 Lennox-Gastaut syndrome, not intractable, with status epilepticus
- G40.812 Lennox-Gastaut syndrome, not intractable, without status epilepticus
- G40.813 Lennox-Gastaut syndrome, intractable, with status epilepticus
- G40.814 Lennox-Gastaut syndrome, intractable, without status epilepticus
- G40.821 Epileptic spasms, not intractable, with status epilepticus
- G40.822 Epileptic spasms, not intractable, without status epilepticus
- G40.823 Epileptic spasms, intractable, with status epilepticus
- G40.824 Epileptic spasms, intractable, without status epilepticus
- G40.833 Dravet syndrome, intractable, with status epilepticus
- G40.834 Dravet syndrome, intractable, without status epilepticus
- G40.841 KCNQ2-related epilepsy, not intractable, with status epilepticus
- G40.842 KCNQ2-related epilepsy, not intractable, without status epilepticus
- G40.843 KCNQ2-related epilepsy, intractable, with status epilepticus
- G40.844 KCNQ2-related epilepsy, intractable, without status epilepticus
- G40.89 Other seizures
- 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
ICD-10-PCS
Procedure Codes
Procedure codes do not drive assignment for this DRG. DRG 101 is a Medical DRG, assigned from the principal diagnosis above.
Frequently Asked Questions
What is MS-DRG 101?
MS-DRG 101 (Seizures without MCC) is a medical DRG in MDC 01 (Diseases & Disorders of the Nervous System). Its FY 2026 relative weight is 0.9026 with a geometric mean length of stay of 2.6 days.
What is the difference between DRG 100, 101?
All 2 share the same base category; the severity of secondary diagnoses separates them: 100 (with MCC), 101 (without MCC). A major complication or comorbidity (MCC) places the case in the highest-weighted DRG of the family; a CC in the middle; neither in the lowest.
How many diagnosis codes group to DRG 101?
62 ICD-10-CM principal diagnosis codes group to this DRG, spanning 2 three-character categories.
What is the relative weight of DRG 101?
The FY 2026 relative weight of this DRG is 0.9026, meaning reimbursement of roughly 0.90 times the average Medicare inpatient case. Multiply by a hospital's blended base rate for the approximate payment.
Source: CMS ICD-10 MS-DRG v43.0 Definitions Manual and the FY 2026 IPPS Final Rule (Table 5), effective October 1, 2025 through September 30, 2026. We publish the DRG assignments as CMS defines them and add the navigation, search, and code links.
