S42.443K — Displaced fracture (avulsion) of medial epicondyle of unspecified humerus, subsequent encounter for fracture with nonunion
Is S42.443K billable?
Yes, but S42.443K will trip a Medicare edit. S42.443K is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, CMS lists S42.443K under Medicare Code Editor edit 20, “Unspecified code” — meaning a code specifying laterality (right, left or bilateral) exists in the same family. On an inpatient claim this triggers the edit, because CMS holds that there are very limited circumstances in which laterality cannot be documented.
More specific alternatives
- S42.441KDisplaced fracture (avulsion) of medial epicondyle of right humerus, subsequent encounter for fracture with nonunion
- S42.442KDisplaced fracture (avulsion) of medial epicondyle of left humerus, subsequent encounter for fracture with nonunion
- S42.444KNondisplaced fracture (avulsion) of medial epicondyle of right humerus, subsequent encounter for fracture with nonunion
- S42.445KNondisplaced fracture (avulsion) of medial epicondyle of left humerus, subsequent encounter for fracture with nonunion
- S42.447KIncarcerated fracture (avulsion) of medial epicondyle of right humerus, subsequent encounter for fracture with nonunion
- S42.448KIncarcerated fracture (avulsion) of medial epicondyle of left humerus, subsequent encounter for fracture with nonunion
S42.443K at a glance
| Code | S42.443K |
|---|---|
| Description | Displaced fracture (avulsion) of medial epicondyle of unspecified humerus, subsequent encounter for fracture with nonunion |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
| 7th character "K" | subsequent encounter for fracture with nonunion |
What does the 7th character "K" mean in S42.443K?
In S42.443K, the 7th character K means subsequent encounter for fracture with nonunion. The 7th character is required for S42.443K to be a valid, complete code.
Same condition, different episode of care — switch the 7th character:
- Ainitial encounter for closed fractureS42.443A
- Binitial encounter for open fractureS42.443B
- Dsubsequent encounter for fracture with routine healingS42.443D
- Gsubsequent encounter for fracture with delayed healingS42.443G
- Ksubsequent encounter for fracture with nonunionS42.443K
- Psubsequent encounter for fracture with malunionS42.443P
- SsequelaS42.443S
What Medicare edits apply to S42.443K?
The Medicare Code Editor screens inpatient claims before they are grouped. These edits name S42.443K directly.
A code specifying laterality (right, left or bilateral) exists in the same family. CMS holds that there are very limited circumstances in which laterality cannot be documented.
Which MS-DRGs does S42.443K group to?
S42.443K 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
As a secondary diagnosis, S42.443K is a complication or comorbidity (CC), which can move a stay into a higher-paying DRG.
How is S42.443K listed in the Alphabetic Index?
The Alphabetic Index lists these routes under S42.44, the nearest indexed parent of S42.443K. Use them to find the family, then select the specific code.
- Fracture, traumatic › humerus › lower end › epicondyle › medial (abduction) (adduction) (separation)
- Fracture, traumatic › humerus › lower end › epicondyle › medial › incarcerated (abduction) (adduction) (separation)
- Fracture, traumatic › humerus › lower end › epicondyle › medial › nondisplaced (abduction) (adduction) (separation)
Excludes1 — never code together — inherited from S42
The conditions below can never be reported together with S42.443K on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
- traumatic amputation of shoulder and upper arm (S48.-)
Use additional code — inherited from Chapter 19
Report an additional code alongside S42.443K to fully describe the condition. S42.443K is sequenced first.
- code to identify any retained foreign body, if applicable (Z18.-)
Excludes2 — not included here — inherited from Chapter 19
The conditions below are not part of S42.443K, but a patient may have both at the same time. When documentation supports it, S42.443K and the excluded code may both be reported.
Excludes2 — not included here — inherited from S40-S49
The conditions below are not part of S42.443K, but a patient may have both at the same time. When documentation supports it, S42.443K and the excluded code may both be reported.
Excludes2 — not included here — inherited from S42
The conditions below are not part of S42.443K, but a patient may have both at the same time. When documentation supports it, S42.443K and the excluded code may both be reported.
- periprosthetic fracture around internal prosthetic shoulder joint (M97.3)
Excludes2 — not included here — inherited from S42.4
The conditions below are not part of S42.443K, but a patient may have both at the same time. When documentation supports it, S42.443K and the excluded code may both be reported.
How long has S42.443K existed?
S42.443K 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.