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ICD-10-CM 2027

ICD-10 code for diaphragm malformation

Q79.1

Other congenital malformations of diaphragm

From the official ICD-10-CM alphabetic index entry “Malformation (congenital) › diaphragm”. Page updated September 29, 2026.

About coding diaphragm malformation

The ICD-10-CM code for diaphragm malformation is Q79.1 (Other congenital malformations of diaphragm).

Within Q79, choose Q79.1 (Other congenital malformations of diaphragm) only when documentation doesn't support a more specific option: congenital diaphragmatic hernia (Q79.0), Exomphalos (Q79.2), gastroschisis (Q79.3), prune belly syndrome (Q79.4), other congenital malformations of abdominal wall (Q79.5), Ehlers-Danlos syndromes (Q79.6), other congenital malformations of musculoskeletal system (Q79.8) and congenital malformation of musculoskeletal system, unspecified (Q79.9).

As a secondary diagnosis it is an MCC (major complication or comorbidity), which can move an inpatient stay into the highest-paying "with MCC" MS-DRG of its family, unless the principal diagnosis excludes it.

In MS-DRG v44.0, it is part of the grouping logic for DRG 205 (Other Respiratory System Diagnoses with MCC, relative weight 1.8244) and DRG 206 (Other Respiratory System Diagnoses without MCC, relative weight 0.9257), in MDC 04 (Diseases and Disorders of the Respiratory System), 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 diaphragm malformation ICD-10 codes

What is the ICD-10 code for diaphragm malformation?

Q79.1 — Other congenital malformations of diaphragm.

Is Q79.1 billable?

Yes. Q79.1 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can Q79.1 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict Q79.1 as a principal diagnosis.

Is Q79.1 a CC or MCC?

Q79.1 is an MCC (major complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.