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S42.221A vs S42.221B

S42.221A (2-part displaced fracture of surgical neck of right humerus, initial encounter for closed fracture) compared with S42.221B (2-part displaced fracture of surgical neck of right humerus, initial encounter for open fracture), from the official CMS tabular data. S42.221A and S42.221B code the same injury at a different phase of treatment. MedCoder-derived

Can these codes be reported together?

Review

Encounter relationship

S42.221A
Initial encounter
2-part displaced fracture of surgical neck of right humerus, initial encounter for closed fracture
↔
S42.221B
Initial encounter
2-part displaced fracture of surgical neck of right humerus, initial encounter for open fracture

What we found

Same injury, other encounter phase.S42.221A and S42.221B code the same injury at a different phase of treatment, set by the 7th character.

The 7th character records the type of care given at the encounter being coded (ICD-10-CM Official Guidelines, Section I.C.19.a), so one encounter takes one of these, not both.

What to review

Use the 7th character that matches the encounter being coded (initial, subsequent or sequela); one encounter takes one of them.

Guide: 7th characters: initial, subsequent, sequelaCheck these on a claim

Why it matters

The 7th character records the phase of care for the encounter being coded, so a single encounter takes one of these characters, not several. Review whether both phases belong on the same episode of care.

Source / rule

ICD-10-CM Official Guidelines, Section I.C.19.a

Side by side

S42.221A2-part displaced fracture of surgical neck of right humerus, initial encounter for closed fractureS42.221B2-part displaced fracture of surgical neck of right humerus, initial encounter for open fracture
Billing statusBillableBillable
ClassificationS00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88)S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88)
Definition2-part displaced fracture of surgical neck of right humerus, initial encounter for closed fracture is a billable ICD-10-CM diagnosis code (S42.221A).2-part displaced fracture of surgical neck of right humerus, initial encounter for open fracture is a billable ICD-10-CM diagnosis code (S42.221B).
7th characterThe appropriate 7th character is to be added to all codes from category S42The appropriate 7th character is to be added to all codes from category S42
Includes
injuries of axilla
injuries of scapular region
injuries of axilla
injuries of scapular region
Excludes1
traumatic amputation of shoulder and upper arm (S48.-)
traumatic amputation of shoulder and upper arm (S48.-)
Excludes2
fracture of shaft of humerus (S42.3-)
physeal fracture of upper end of humerus (S49.0-)
periprosthetic fracture around internal prosthetic shoulder joint (M97.3)
burns and corrosions (T20-T32)
frostbite (T33-T34)
injuries of elbow (S50-S59)
insect bite or sting, venomous (T63.4)
fracture of shaft of humerus (S42.3-)
physeal fracture of upper end of humerus (S49.0-)
periprosthetic fracture around internal prosthetic shoulder joint (M97.3)
burns and corrosions (T20-T32)
frostbite (T33-T34)
injuries of elbow (S50-S59)
insect bite or sting, venomous (T63.4)

Notes are the code’s own tabular entry, quoted as published. A note that names the other code is the one the verdict above rests on.

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Derived from the official CMS ICD-10-CM tabular data (FY2026). A coding-rule comparison, not billing advice: payer-specific edits and medical-necessity policy are outside its scope. All data sources