ICD-10-CM 2027
ICD-10 code for CDKL5
From the official ICD-10-CM alphabetic index entry “CDKL5 (Cyclin-Dependent Kinase-Like 5 Deficiency Disorder)”. Page updated September 29, 2026.
About coding CDKL5
The ICD-10-CM code for CDKL5 is G40.42 (Cyclin-Dependent Kinase-Like 5 Deficiency Disorder).
Within G40.4 (other generalized epilepsy and epileptic syndromes), G40.42 is specifically for Cyclin-Dependent Kinase-Like 5 Deficiency Disorder. Related codes cover not intractable (G40.40) and intractable (G40.41).
Use an additional code, if known, to identify associated manifestations, such as: cortical blindness (H47.61-) and global developmental delay (F88).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
Common questions about CDKL5 ICD-10 codes
What is the ICD-10 code for CDKL5?
- G40.42 — Cyclin-Dependent Kinase-Like 5 Deficiency Disorder.
Is G40.42 billable?
- Yes. G40.42 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can G40.42 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict G40.42 as a principal diagnosis.
Is G40.42 a CC or MCC?
- No. G40.42 is neither a CC nor an MCC under MS-DRG v44.0.