ICD-10-CM 2027
ICD-10 code for Meloschisis
From the official ICD-10-CM alphabetic index entry “Meloschisis”. Page updated September 29, 2026.
About coding Meloschisis
The ICD-10-CM code for Meloschisis is Q18.4 (Macrostomia).
Within Q18 (other congenital malformations of face and neck), Q18.4 is specifically for Macrostomia. Related codes cover sinus, fistula and cyst of branchial cleft (Q18.0), preauricular sinus and cyst (Q18.1), other branchial cleft malformations (Q18.2), Webbing of neck (Q18.3), Microstomia (Q18.5), Macrocheilia (Q18.6), Microcheilia (Q18.7), other specified congenital malformations of face and neck (Q18.8) and 1 more.
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 157 (Dental and Oral Diseases with MCC, relative weight 1.809), DRG 158 (Dental and Oral Diseases with CC, relative weight 0.9366) and DRG 159 (Dental and Oral Diseases without CC/MCC, relative weight 0.6893), in MDC 03 (Diseases and Disorders of the Ear, Nose, Mouth and Throat), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
Common questions about Meloschisis ICD-10 codes
What is the ICD-10 code for Meloschisis?
- Q18.4 — Macrostomia.
Is Q18.4 billable?
- Yes. Q18.4 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can Q18.4 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict Q18.4 as a principal diagnosis.
Is Q18.4 a CC or MCC?
- No. Q18.4 is neither a CC nor an MCC under MS-DRG v44.0.