Skip to content
Dx

ICD-10-CM 2027 diagnosis code

Q34.9Congenital malformation of respiratory system, unspecified

✓ Billable / specificPOA exempt

Q34.9 is a valid, billable ICD-10-CM code for congenital malformation of respiratory system, unspecified. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About Q34.9

Q34.9 is the ICD-10-CM diagnosis code for congenital malformation of respiratory system, unspecified. It belongs to category Q34 (other congenital malformations of respiratory system), block Q30-Q34 (congenital malformations of the respiratory system) and chapter 17 (congenital malformations, deformations, chromosomal abnormalities, and genetic disorders). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within Q34, choose Q34.9 (Congenital malformation of respiratory system, unspecified) only when documentation doesn't support a more specific option: anomaly of pleura (Q34.0), congenital cyst of mediastinum (Q34.1) and other specified congenital malformations of respiratory system (Q34.8).

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 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.

It is exempt from present-on-admission (POA) reporting, so no POA indicator is required.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 748.9 (unspecified anomaly of respiratory system).

Coding notes

Applicable toConditions and synonyms classified to this code
  • Congenital absence of respiratory system
  • Congenital anomaly of respiratory system NOS

Notes that apply from higher levels

Instructions written at a parent level also apply to Q34.9.

› From Q34 Other congenital malformations of respiratory system
Excludes2
  • congenital central alveolar hypoventilation syndrome (G47.35)

Broader instructions also apply from Chapter 17: Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders.

Alphabetic index entries

6 entries

Terms in the official ICD-10-CM index that lead to Q34.9.

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

ICD-9-CM equivalent

Converter →
  • 748.9Unspecified anomaly of respiratory systemexact

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about Q34.9

Is Q34.9 billable?

Yes. Q34.9 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can Q34.9 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict Q34.9 as a principal diagnosis.

Is Q34.9 a CC or MCC?

No. Q34.9 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does Q34.9 group to?

Q34.9 is used in the MS-DRG v44.0 logic for MS-DRG 205 (Other Respiratory System Diagnoses with MCC) and MS-DRG 206 (Other Respiratory System Diagnoses without MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.

What is the ICD-9 code for Q34.9?

The CMS General Equivalence Mappings map Q34.9 to ICD-9-CM 748.9.