S42.343B — Displaced spiral fracture of shaft of humerus, unspecified arm, initial encounter for open fracture
Is S42.343B billable?
Yes, but S42.343B will trip a Medicare edit. S42.343B is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, CMS lists S42.343B 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
- S42.341BDisplaced spiral fracture of shaft of humerus, right arm, initial encounter for open fracture
- S42.342BDisplaced spiral fracture of shaft of humerus, left arm, initial encounter for open fracture
- S42.344BNondisplaced spiral fracture of shaft of humerus, right arm, initial encounter for open fracture
- S42.345BNondisplaced spiral fracture of shaft of humerus, left arm, initial encounter for open fracture
S42.343B at a glance
| Code | S42.343B |
|---|---|
| Description | Displaced spiral fracture of shaft of humerus, unspecified arm, initial encounter for open fracture |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
| 7th character "B" | initial encounter for open fracture |
What does the 7th character "B" mean in S42.343B?
In S42.343B, the 7th character B means initial encounter for open fracture. The 7th character is required for S42.343B to be a valid, complete code.
Same condition, different episode of care — switch the 7th character:
- Ainitial encounter for closed fractureS42.343A
- Binitial encounter for open fractureS42.343B
- Dsubsequent encounter for fracture with routine healingS42.343D
- Gsubsequent encounter for fracture with delayed healingS42.343G
- Ksubsequent encounter for fracture with nonunionS42.343K
- Psubsequent encounter for fracture with malunionS42.343P
- SsequelaS42.343S
What Medicare edits apply to S42.343B?
The Medicare Code Editor screens inpatient claims before they are grouped. These edits name S42.343B 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 S42.343B group to?
S42.343B sits in MDC 08 and helps define the logic of 2 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 562Fracture, Sprain, Strain and Dislocation Except Femur, Hip, Pelvis and Thigh with MCCmedical
- 563Fracture, Sprain, Strain and Dislocation Except Femur, Hip, Pelvis and Thigh without MCCmedical
As a secondary diagnosis, S42.343B is a major complication or comorbidity (MCC), which can move a stay into a higher-paying DRG. It also carries Hospital-Acquired Condition category 05.
How is S42.343B listed in the Alphabetic Index?
The Alphabetic Index lists these routes under S42.34, the nearest indexed parent of S42.343B. Use them to find the family, then select the specific code.
- Fracture, traumatic › humerus › shaft › spiral (abduction) (adduction) (separation)
- Fracture, traumatic › humerus › shaft › spiral › nondisplaced (abduction) (adduction) (separation)
Excludes1 — never code together — inherited from S42
The conditions below can never be reported together with S42.343B 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 S42.343B to fully describe the condition. S42.343B 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 S42.343B, but a patient may have both at the same time. When documentation supports it, S42.343B and the excluded code may both be reported.
Excludes2 — not included here — inherited from S40-S49
The conditions below are not part of S42.343B, but a patient may have both at the same time. When documentation supports it, S42.343B and the excluded code may both be reported.
Excludes2 — not included here — inherited from S42
The conditions below are not part of S42.343B, but a patient may have both at the same time. When documentation supports it, S42.343B and the excluded code may both be reported.
- periprosthetic fracture around internal prosthetic shoulder joint (M97.3)
Excludes2 — not included here — inherited from S42.3
The conditions below are not part of S42.343B, but a patient may have both at the same time. When documentation supports it, S42.343B and the excluded code may both be reported.
How long has S42.343B existed?
S42.343B 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.