Q66.91 — Congenital deformity of feet, unspecified, right foot
Is Q66.91 billable?
Yes, but Q66.91 is an unspecified code. Q66.91 is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, Q66.91 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 Q66.91 — the more specific alternatives are listed below.
Q66.91 at a glance
| Code | Q66.91 |
|---|---|
| Description | Congenital deformity of feet, unspecified, right foot |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Which MS-DRGs does Q66.91 group to?
Q66.91 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 Q66.91 listed in the Alphabetic Index?
The Alphabetic Index lists these routes under Q66.9, the nearest indexed parent of Q66.91. Use them to find the family, then select the specific code.
- Distortion › foot (s) (congenital)
- Distortion › toe (s) (congenital)
- Deformity › foot › congenital NOS
- Deformity › metatarsus › congenital
- Deformity › toe › congenital
- Malposition › congenital › foot
- Malposition › congenital › toe
Excludes1 — never code together — inherited from Q66
The conditions below can never be reported together with Q66.91 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
Excludes2 — not included here — inherited from Chapter 17
The conditions below are not part of Q66.91, but a patient may have both at the same time. When documentation supports it, Q66.91 and the excluded code may both be reported.
- inborn errors of metabolism (E70-E88)
How long has Q66.91 existed?
Q66.91 first appears in FY2021 (FY2020 is not available, so it may have appeared then).
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.