G40.842 — KCNQ2-related epilepsy, not intractable, without status epilepticus
Is G40.842 billable?
Yes — G40.842 is billable for FY2027. G40.842 is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. G40.842 may be submitted for encounters from October 1, 2026 through September 30, 2027.
G40.842 at a glance
| Code | G40.842 |
|---|---|
| Description | KCNQ2-related epilepsy, not intractable, without status epilepticus |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Which MS-DRGs does G40.842 group to?
G40.842 sits in MDC 01 and helps define the logic of 1 MS-DRG (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 023Craniotomy with Major Device Implant or Acute Complex CNS Principal Diagnosis with MCC or Antineoplastic Implant or Epilepsy with Neurostimulatorsurgical
As a secondary diagnosis, G40.842 is a complication or comorbidity (CC), which can move a stay into a higher-paying DRG.
How is G40.842 listed in the Alphabetic Index?
These are the routes through the Alphabetic Index that lead to G40.842. They show the wording a clinician may have documented, which often differs from the Tabular description.
- Epilepsy, epileptic, epilepsia › KCNQ2-related (attack) (cerebral) (convulsion) (fit) (seizure)
- Epilepsy, epileptic, epilepsia › KCNQ2-related › not intractable (attack) (cerebral) (convulsion) (fit) (seizure)
- Epilepsy, epileptic, epilepsia › KCNQ2-related › not intractable › without status epilepticus (attack) (cerebral) (convulsion) (fit) (seizure)
Inclusion terms
Alternative wording in documentation that is classified to G40.842.
- KCNQ2-related epilepsy NOS
Excludes1 — never code together — inherited from G40
The conditions below can never be reported together with G40.842 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
Excludes2 — not included here — inherited from Chapter 6
The conditions below are not part of G40.842, but a patient may have both at the same time. When documentation supports it, G40.842 and the excluded code may both be reported.
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Excludes2 — not included here — inherited from G40
The conditions below are not part of G40.842, but a patient may have both at the same time. When documentation supports it, G40.842 and the excluded code may both be reported.
How long has G40.842 existed?
G40.842 first appears in FY2025.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.