G40.21Header code — not billable

Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, intractable

Short description: Local-rel (focal) symptc epi w complex partial seiz, ntrct

Chapter
6. Diseases of the nervous system
Category
G40
Effective date
October 1, 2026

Related codes in category G40

G40Epilepsy and recurrent seizuresG40.0Local-rel (focal) idio epilepsy w seizures of loc onsetG40.00Local-rel (focal) idio epi w seiz of loc onset, not ntrctG40.001Local-rel idio epi w seiz of loc onst, not ntrct, w stat epiYesG40.009Local-rel idio epi w seiz of loc onst,not ntrct,w/o stat epiYesG40.01Local-rel (focal) idio epi w seizures of loc onset, ntrctG40.011Local-rel idio epi w seiz of loc onset, ntrct, w stat epiYesG40.019Local-rel idio epi w seiz of loc onset, ntrct, w/o stat epiYesG40.1Local-rel (focal) symptc epilepsy w simple partial seizuresG40.10Local-rel symptc epi w simple partial seiz, not ntrctG40.101Local-rel symptc epi w simp part seiz, not ntrct, w stat epiYesG40.109Local-rel symptc epi w simp prt seiz,not ntrct, w/o stat epiYes

Frequently asked questions

What is ICD-10 code G40.21?

G40.21 is an ICD-10-CM diagnosis code for Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, intractable.

Is G40.21 a billable code?

No. G40.21 is a category/header code, not billable on its own — use one of its more specific child codes instead.

What ICD-10-CM chapter is G40.21 in?

G40.21 falls under Chapter 6: Diseases of the nervous system.

When did G40.21 become effective?

G40.21 has been effective since October 1, 2026, per the CMS/CDC ICD-10-CM annual release.

What other codes are related to G40.21?

G40.21 belongs to category G40, which includes 12 other codes — see the related codes list on this page.

ICD-10-CM data maintained by CDC/CMS (public domain). Always verify codes with authoritative sources before making coding or billing decisions.