S21.05 ICD-10-CM Code: Open bite of breast
Billing Status: NO. This is a clinician non-billable / parent hierarchy grouping in the ICD-10-CM system.
Official Registry Overview & Definition
Official Tabular Instructional Notes
Sequencing, inclusion, and exclusion notes published for S21.05 in the official ICD-10-CM tabular list.
Includes
Conditions the official ICD-10-CM tabular list includes under this code.
- injuries of breast
- injuries of chest (wall)
- injuries of interscapular area
Inclusion Terms
Alternative terms the tabular list files under this code.
- Bite of breast NOS
Excludes1 — Not Coded Here
Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
- superficial bite of breast (S20.17) Compare S21.05 vs S20.17 →
- traumatic amputation (partial) of thorax (S28.1) Compare S21.05 vs S28.1 →
Excludes2 — Not Included Here
Conditions not covered by this code, but which may be reported alongside it when both are present.
- burns and corrosions (T20-T32) Compare S21.05 vs T20 →
- effects of foreign body in bronchus (T17.5) Compare S21.05 vs T17.5 →
- effects of foreign body in esophagus (T18.1) Compare S21.05 vs T18.1 →
- effects of foreign body in lung (T17.8) Compare S21.05 vs T17.8 →
- effects of foreign body in trachea (T17.4) Compare S21.05 vs T17.4 →
- frostbite (T33-T34) Compare S21.05 vs T33 →
- injuries of axilla
- injuries of clavicle
- injuries of scapular region
- injuries of shoulder
- insect bite or sting, venomous (T63.4) Compare S21.05 vs T63.4 →
Code Also
Additional codes that may be required to fully describe the encounter.
- any associated injury, such as:
- injury of heart (S26.-)
- injury of intrathoracic organs (S27.-)
- rib fracture (S22.3-, S22.4-)
- spinal cord injury (S24.0-, S24.1-)
- traumatic hemopneumothorax (S27.3)
- traumatic hemothorax (S27.1)
- traumatic pneumothorax (S27.0)
- wound infection
Change history
No changes recorded for this code — unchanged since the FY2016 baseline of the change ledger.
Verify Before Coding
- Not billable as written — a more specific code is required: S21.051A, S21.051D, S21.051S, S21.052A, S21.052D.
- Requires a 7th character. "The appropriate 7th character is to be added to each code from category S21" Options: S21.051A, S21.051D, S21.051S, S21.052A, S21.052D, S21.052S
From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim.
Contextual Map
Every relationship of S21.05 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.
Hierarchy
- S00-T88 — Chapter 19: Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88) (S00-T88) [Hierarchy]
Excludes1
- S20.17 — Other superficial bite of breast [Excludes1]: “superficial bite of breast (S20.17)” · check together
Referenced by Excludes1 notes
- S20.17 — Other superficial bite of breast [Excludes1]: “open bite of breast (S21.05-)” · check together
Referenced by Code Also instructions
- S23.1 — Subluxation and dislocation of thoracic vertebra [Code Also](via S21.-): “open wound of thorax (S21.-)” · check together
- S24 — Injury of nerves and spinal cord at thorax level [Code Also](via S21.-): “open wound of thorax (S21.-)” · check together
- S25 — Injury of blood vessels of thorax [Code Also](via S21.-): “any associated open wound (S21.-)” · check together
- S26 — Injury of heart [Code Also](via S21.-): “open wound of thorax (S21.-)” · check together
- S27 — Injury of other and unspecified intrathoracic organs [Code Also](via S21.-): “any associated open wound of thorax (S21.-)” · check together
- S29 — Other and unspecified injuries of thorax [Code Also](via S21.-): “any associated open wound (S21.-)” · check together
Nearest codes (40)
- S21 — Open wound of thorax [Sibling]
- S21.032A — Puncture wound without foreign body of left breast, initial encounter [Sibling]
- S21.032D — Puncture wound without foreign body of left breast, subsequent encounter [Sibling]
- S21.032S — Puncture wound without foreign body of left breast, sequela [Sibling]
- S21.039 — Puncture wound without foreign body of unspecified breast [Sibling]
- S21.039A — Puncture wound without foreign body of unspecified breast, initial encounter [Sibling]
- S21.039D — Puncture wound without foreign body of unspecified breast, subsequent encounter [Sibling]
- S21.039S — Puncture wound without foreign body of unspecified breast, sequela [Sibling]
- and 32 more
Referenced by Other Codes
Official ICD-10-CM tabular notes on other codes that name S21.05 or its code family.
1 Excludes1 notes: S20.17.
6 Code Also instructions: S23.1 (via S21.-), S24 (via S21.-), S25 (via S21.-), S26 (via S21.-), S27 (via S21.-), S29 (via S21.-).
Frequently Asked Questions (FAQ) & Clinical Guidance
Can S21.05 be billed directly?
No. S21.05 (Open bite of breast) is a non-billable ICD-10-CM category code. A more specific billable subcode must be selected based on clinical documentation.
Does S21.05 require a 7th character?
Yes. The appropriate 7th character is to be added to each code from category S21.
Nearest Codes in This Family
Official ICD-10-CM classifications closest to S21.05 in its code family, with their registry titles.
- S21.042S — Puncture wound with foreign body of left breast, sequela
- S21.049 — Puncture wound with foreign body of unspecified breast
- S21.049A — Puncture wound with foreign body of unspecified breast, initial encounter
- S21.049D — Puncture wound with foreign body of unspecified breast, subsequent encounter
- S21.049S — Puncture wound with foreign body of unspecified breast, sequela
- S21.051 — Open bite of right breast
- S21.051A — Open bite of right breast, initial encounter
- S21.051D — Open bite of right breast, subsequent encounter
- S21.051S — Open bite of right breast, sequela
- S21.052 — Open bite of left breast