Q34.1
Congenital cyst of mediastinum
Q34.1 (also written Q341) is a billable ICD-10-CM diagnosis code for congenital cyst of mediastinum. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 4 codes in category Q34 (Other congenital malformations of respiratory system). The Alphabetic Index lists it under 2 entries. Its coding notes include 2 Excludes2 entries.
Guidelines tip
From the FY2027 Official Guidelines. ICD10Ref adds no rules of its own.
Chapter 17 codes can be used for life. Manifestations that are an inherent part of a specifically coded anomaly are not coded separately. A corrected malformation is reported with a personal history code.
Excludes2
Not included here. Both codes may be reported if the patient has both conditions.
- congenital central alveolar hypoventilation syndrome (G47.35)
Also from chapter/block level (1 note)
- inborn errors of metabolism (E70-E88)
Care settings
How CMS programs treat this code. These are CMS claim edits and list entries, not coverage or eligibility rules.
Home Health Primary
Accepted as the primary (principal) diagnosis on a home health claim. The Home Health Grouper assigns it to the MMTA - Other clinical group.
Source: CMS Home Health Grouper Software v07.2.26, effective October 1, 2026Notes
Also from chapter/block level (1 note)
- Codes from this chapter are not for use on maternal records
Alphabetic Index terms
Terms the official Alphabetic Index lists for this code. 2 entries