Q23.2
Congenital mitral stenosis
Q23.2 (also written Q232) is a billable ICD-10-CM diagnosis code for congenital mitral stenosis. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 9 codes in category Q23 (Congenital malformations of aortic and mitral valves). The Alphabetic Index lists it under 16 entries. Its coding notes include 1 Excludes2 entry.
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.
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, 2026Hospital CC
Counts as a complication or comorbidity (CC) when reported as a secondary diagnosis on an inpatient claim. It does not count when the principal diagnosis is one of the 66 codes in its exclusion list. Some MS-DRGs also ignore a CC or MCC that defines the DRG.
Source: CMS MS-DRG Definitions Manual v44, effective October 1, 2026, Appendix CInclusion terms
Conditions classified to this code.
- Congenital mitral atresia
Notes
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. 16 entries
- Anomaly, anomalous (congenital) (unspecified type), heart, valve NEC, mitral, stenosis
- Anomaly, anomalous (congenital) (unspecified type), mitral (leaflets) (valve), stenosis
- Atresia, atretic, mitral valve
- Deformity, mitral (leaflets) (valve), parachute
- Deformity, mitral (leaflets) (valve), stenosis, congenital
- Disease, diseased, Duroziez's (congenital mitral stenosis)
- Duroziez's disease (congenital mitral stenosis)
- Fusion, fused (congenital), commissure, mitral valve
- Fusion, fused (congenital), cusps, heart valve NEC, mitral
- Parachute mitral valve
- Stenosis, stenotic (cicatricial), mitral (chronic) (inactive) (valve), congenital
- Stenosis, stenotic (cicatricial), valve (cardiac) (heart), congenital, mitral