Q79.9 — Congenital malformation of musculoskeletal system, unspecified

BillableUnspecified

Is Q79.9 billable?

Yes, but Q79.9 is an unspecified code. Q79.9 is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, Q79.9 is an unspecified or catch-all code. Payers apply additional scrutiny to unspecified codes and many deny them when the medical record supports a more specific option, so check the documentation before selecting Q79.9 — the more specific alternatives are listed below.

More specific alternatives

Q79.9 at a glance

Code	Q79.9
Description	Congenital malformation of musculoskeletal system, unspecified
Billable	Yes
Code set	ICD-10-CM FY2027
Valid for encounters	October 1, 2026 – September 30, 2027

Which MS-DRGs does Q79.9 group to?

Q79.9 sits in MDC 08 and helps define the logic of 3 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.

564Other Musculoskeletal System and Connective Tissue Diagnoses with MCCmedical
565Other Musculoskeletal System and Connective Tissue Diagnoses with CCmedical
566Other Musculoskeletal System and Connective Tissue Diagnoses without CC/MCCmedical

How is Q79.9 listed in the Alphabetic Index?

These are the routes through the Alphabetic Index that lead to Q79.9. They show the wording a clinician may have documented, which often differs from the Tabular description.

Agenesis › bone
Agenesis › cartilage
Anomaly, anomalous › bone (congenital) (unspecified type)
Anomaly, anomalous › bursa (congenital) (unspecified type)
Anomaly, anomalous › fascia (congenital) (unspecified type)
Anomaly, anomalous › ligament (congenital) (unspecified type)
Anomaly, anomalous › muscle (congenital) (unspecified type)
Anomaly, anomalous › musculoskeletal system, except limbs (congenital) (unspecified type)
Anomaly, anomalous › tendon (congenital) (unspecified type)
Deformity › bursa, congenital
Development › abnormal, bone
Elongated, elongation › bone (congenital)

Inclusion terms

Alternative wording in documentation that is classified to Q79.9.

Congenital anomaly of musculoskeletal system NOS
Congenital deformity of musculoskeletal system NOS

Excludes2 — not included here — inherited from Chapter 17

The conditions below are not part of Q79.9, but a patient may have both at the same time. When documentation supports it, Q79.9 and the excluded code may both be reported.

inborn errors of metabolism (E70-E88)

Excludes2 — not included here — inherited from Q79

The conditions below are not part of Q79.9, but a patient may have both at the same time. When documentation supports it, Q79.9 and the excluded code may both be reported.

congenital (sternomastoid) torticollis (Q68.0)

How long has Q79.9 existed?

Q79.9 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.

Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.