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S50.84 ICD-10-CM Code: External constriction of forearm

Billing Status: NO. This is a clinician non-billable / parent hierarchy grouping in the ICD-10-CM system.

Coding at a Glance

7th character
Required — see the character table on this page
Tabular directives
5 Excludes2

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for S50.84 in the official ICD-10-CM tabular list, quoted as published.

Notes without a marker are published on S50.84 itself; “inherited from” names the category or block whose note applies here.

Excludes2 — Not Included Here

Conditions not covered by this code, but which may be reported alongside it when both are present.

7th Character Guide

"The appropriate 7th character is to be added to each code from category S50"

  • A — initial encounter
  • D — subsequent encounter
  • S — sequela

How the encounter character is assigned. “Initial encounter” means the patient is receiving active treatment for the condition — it is not limited to the first visit, and a different or new provider giving active treatment still assigns it. “Subsequent encounter” covers care during the healing or recovery phase after active treatment. “Sequela” is for complications or conditions that arise as a direct result of the original condition.

ICD-10-CM Official Guidelines for Coding and Reporting, Section I.C.19.a (paraphrased by MedCoder).

Variant codes in this family

S50.841A, S50.841D, S50.841S, S50.842A, S50.842D, S50.842S, S50.849A, S50.849D

Character meanings are CMS's official 7th-character extensions for this family, as carried in each variant code's official description; variant codes are registry rows. The explanation of how the encounter character is assigned is MedCoder editorial, distinct from the official content above it.

Code Overview

External constriction of forearm is a non-billable ICD-10-CM category code (S50.84). A more specific billable subcode must be selected for claims submission.

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Verify Before Coding

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

Other codes that name S50.84 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 11 Excludes2 notes: S40 — Superficial injury of shoulder and upper arm (via S50.-), S40-S49 — Injuries to the shoulder and upper arm (S40-S49) (via S50.-), S41 — Open wound of shoulder and upper arm (via S50.-), S42 — Fracture of shoulder and upper arm (via S50.-), S43 — Dislocation and sprain of joints and ligaments of shoulder girdle (via S50.-), S44 — Injury of nerves at shoulder and upper arm level (via S50.-), S45 — Injury of blood vessels at shoulder and upper arm level (via S50.-), S46 — Injury of muscle, fascia and tendon at shoulder and upper arm level (via S50.-), S47 — Crushing injury of shoulder and upper arm (via S50.-), S48 — Traumatic amputation of shoulder and upper arm (via S50.-), S49 — Other and unspecified injuries of shoulder and upper arm (via S50.-).

These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.

Related Codes

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main term “Constriction”; these codes share that main term but sit in a different category of the Tabular List.

S30.840 — External constriction of lower back and pelvis (external, pelvis), S30.841 — External constriction of abdominal wall (external, groin), S30.842 — External constriction of penis (external, penis), S30.843 — External constriction of scrotum and testes (external, testis), S30.844 — External constriction of vagina and vulva (external, vulva), S30.845 — External constriction of unspecified external genital organs, male (external, pudendum, male), S30.846 — External constriction of unspecified external genital organs, female (external, pudendum, female), S30.84A — External constriction of flank (external, flank), S40.24 — External constriction of shoulder (external, shoulder), S40.84 — External constriction of upper arm (external, arm), S60.34 — External constriction of thumb (external, thumb), S60.44 — External constriction of fingers (external, finger), S60.54 — External constriction of hand (external, hand), S60.84 — External constriction of wrist (external, wrist), S70.24 — External constriction of hip (external, hip), S70.34 — External constriction of thigh (external, thigh), S80.24 — External constriction of knee (external, knee), S80.84 — External constriction of lower leg (external, leg), S90.44 — External constriction of toe (external, toe), S90.54 — External constriction of ankle (external, ankle), +30 more

Contextual Map

Every relationship of S50.84 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run S50.84 with these 8 related codes in Claim Check

Hierarchy

Referenced by Excludes2 notes (11)

Nearest codes (40)

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Common coding questions

Can S50.84 be billed directly?

No. S50.84 (External constriction of forearm) is a non-billable ICD-10-CM category code. A more specific billable subcode must be selected based on clinical documentation.

Does S50.84 require a 7th character?

Yes. The appropriate 7th character is to be added to each code from category S50.

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data
CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder structured relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    External constriction of forearm

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027 (effective October 1, 2026), and none are recorded for this code. Note changes are tracked from FY2027 only.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to S50.84 in its code family, with their registry titles.

View all codes in the S50 family