Q99Non-billableSave
Q99 - Other chromosome abnormalities, not elsewhere classified
ICD-10-CM Chapter 17: Congenital malformations, deformations and chromosomal abnormalities · Q90-Q99 Chromosomal abnormalities, not elsewhere classified (Q90-Q99) · Top-level category · FY2027
Coding Guidance
Q99 is a non-billable heading. Report one of the 5 more specific codes below.
Includes, Excludes and Coding Notes
Excludes 2 — Not Included HereFrom Q90-Q99 Chromosomal abnormalities, not elsewhere classified (Q90-Q99)
Not part of this code; report both codes when the patient has both conditions.
- mitochondrial metabolic disorders (E88.4-)
Excludes 2 — Not Included HereFrom Chapter Q00-Q99
Not part of this code; report both codes when the patient has both conditions.
- inborn errors of metabolism (E70-E88)
NotesFrom Chapter Q00-Q99
Instructional notes from the ICD-10-CM tabular list.
- Codes from this chapter are not for use on maternal records
More Specific Codes (5)
Related condition guides
Documentation requirements, coding pitfalls and FAQs for conditions coded with Q99.
Chapter Information
Chapter 17: Congenital malformations, deformations and chromosomal abnormalities
Range: Q00-Q99
View full chapterRelated ICD-10 Codes
More specific codes for Q99
Other categories in this chapter
Codes at the same level as Q99
- Anencephaly and similar malformationsQ00
- EncephaloceleQ01
- MicrocephalyQ02
- Congenital hydrocephalusQ03
- Other congenital malformations of brainQ04
- Spina bifidaQ05
- Other congenital malformations of spinal cordQ06
- Other congenital malformations of nervous systemQ07
- Congenital malformations of eyelid, lacrimal apparatus and orbitQ10
- Anophthalmos, microphthalmos and macrophthalmosQ11
- Congenital lens malformationsQ12
- Congenital malformations of anterior segment of eyeQ13
- Congenital malformations of posterior segment of eyeQ14
- Other congenital malformations of eyeQ15
- Congenital malformations of ear causing impairment of hearingQ16
- Other congenital malformations of earQ17
- Other congenital malformations of face and neckQ18
- Congenital malformations of cardiac chambers and connectionsQ20
- Congenital malformations of cardiac septaQ21
- Congenital malformations of pulmonary and tricuspid valvesQ22
- Congenital malformations of aortic and mitral valvesQ23
- Other congenital malformations of heartQ24
- Congenital malformations of great arteriesQ25
- Congenital malformations of great veinsQ26
- Other congenital malformations of peripheral vascular systemQ27
- Other congenital malformations of circulatory systemQ28
- Congenital malformations of noseQ30
- Congenital malformations of larynxQ31
- Congenital malformations of trachea and bronchusQ32
- Congenital malformations of lungQ33
- Other congenital malformations of respiratory systemQ34
- Cleft palateQ35
- Cleft lipQ36
- Cleft palate with cleft lipQ37
- Other congenital malformations of tongue, mouth and pharynxQ38
- Congenital malformations of esophagusQ39
- Other congenital malformations of upper alimentary tractQ40
- Congenital absence, atresia and stenosis of small intestineQ41
- Congenital absence, atresia and stenosis of large intestineQ42
- Other congenital malformations of intestineQ43
48 more in this chapter.