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S42.391B ICD-10-CM Code: Other fracture of shaft of right humerus, initial encounter for open fracture

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FY 2026 Apr update / Injury, poisoning and certain other consequences of external causes (S00-T88) / Injuries to the shoulder and upper arm (S40-S49)

S42.391B

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Other fracture of shaft of right humerus, initial encounter for open fracture

Other fracture of shaft of right humerus, initial encounter for open fracture

CMS-HCC V28

0

0

RAF 0

CMS-HCC V24

0

0

RAF 0

ACA/HHS

0

0

RAF 0

ESRD/PACE

0

0

RAF 0

RXHCC

0

0

RAF 0

Code Trumping

Basket needed

Code Book Path

Official
S42.39Other fracture of shaft of humerus
S42.391Other fracture of shaft of right humerus
S42.391BOther fracture of shaft of right humerus, initial encounter for open fracture

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for S42.391B in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for S42.391B in this effective period.

Related Child Codes

Official
S42.391AOther fracture of shaft of right humerus, initial encounter for closed fracture
S42.391DOther fracture of shaft of right humerus, subsequent encounter for fracture with routine healing
S42.391GOther fracture of shaft of right humerus, subsequent encounter for fracture with delayed healing
S42.391KOther fracture of shaft of right humerus, subsequent encounter for fracture with nonunion
S42.391POther fracture of shaft of right humerus, subsequent encounter for fracture with malunion

Includes

Official

ICD-10-CM does not list Includes notes for S42.391B in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for S42.391B in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for S42.391B in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for S42.391B in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for S42.391B in this effective period.

Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.

Is S42.391B an HCC code?

No. S42.391B is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.

This code does not map to an HCC category in any model (V28, V24, ESRD, RxHCC).

What This Code Means

S42.391B is the ICD-10-CM diagnosis code for other fracture of shaft of right humerus, initial encounter for open fracture. S42.391B sits in the ICD-10-CM chapter for injury, poisoning and certain other consequences of external causes (s00-t88), within the section covering injuries to the shoulder and upper arm (s40-s49).

S42.391B is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.

S42.391B is a billable ICD-10-CM code that can be reported on claims but does not currently contribute to a Medicare Advantage member's RAF score under any CMS risk adjustment model (V28, V24, ESRD, or RxHCC). Coders reviewing S42.391B should check whether additional documentation would support a more specific child code in the same hierarchy that does map to a payment HCC, capturing the correct specificity is the highest-impact RAF improvement available within accurate coding.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for S42.391B sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Child Codes

Code Hierarchy

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