Crystal's MCW Coder Hub🩺 CPT Code 13100 - Repair, Complex, Trunk; 1.1 cm to 2.5 cm
📋 Code Description
Repair, complex, trunk; 1.1 cm to 2.5 cm
CPT 13100 describes the complex repair of a wound located on the trunk measuring between 1.1 cm and 2.5 cm in total length. Complex repair is the most involved category of wound closure in the CPT integumentary repair section and requires one or more of the following in addition to the layered closure itself:
- Scar revision
- Debridement (e.g., traumatic lacerations, avulsions)
- Extensive undermining of tissue
- Stents
- Retention sutures
Important
The complexity is driven by the nature of the wound and the technique required, not by the simple depth of closure. A complex repair inherently involves more physician work, greater risk, and a higher level of skill than simple or intermediate repairs of the same size.
🗂️ Code Type & Classification
| Field | Detail |
|---|---|
| CPT Code | 13100 |
| Code Type | Category I CPT |
| Section | Surgery - Integumentary System |
| Subsection | Repair (Closure) |
| Repair Type | Complex |
| Anatomic Site | Trunk |
| Size Range | 1.1 cm - 2.5 cm |
| Global Period | 90 days |
| wRVU | 3.15 |
| Assistant Payable | ❌ No (generally not payable) |
| Bilateral | ❌ Not applicable |
| Add-On Code | ❌ No (but see 13102) |
| Facility/Non-Fac | Both settings applicable |
🧭 Anatomic Site — “Trunk” Defined
For purposes of complex repair coding, the trunk includes:
- Chest (anterior and posterior thorax)
- Back
- Abdomen (including flanks and sides)
- Perineum
- Genitalia (external)
- Buttocks
⚠️ Important: The neck, axillae, hands, and feet are not included under trunk for complex repair — those areas map to 13131-13133.
🔬 What Qualifies as a “Complex” Repair?
A complex repair must involve more than layered closure alone. At least one of the following elements must be documented:
| Element | Description |
|---|---|
| Scar revision | Excision of existing scar with wound edge freshening prior to closure |
| Debridement | Removal of devitalized, contaminated, or foreign tissue |
| Extensive undermining | Wide separation of skin/subcutaneous tissue from underlying fascia to allow tension-free closure |
| Stents | Use of bolster or stent sutures to reduce wound tension |
| Retention sutures | Heavy through-and-through sutures placed to reinforce the primary closure |
📝 Documentation Tip: The operative note must explicitly describe why the repair was complex. “Layered closure” alone does not support complex repair coding. Phrases such as “extensive undermining performed,” “debridement of devitalized tissue prior to closure,” or “retention sutures placed due to wound tension” are necessary.
📐 Wound Measurement Rules
- Measure total wound length in centimeters (cm), not inches
- When multiple wounds are repaired in the same classification (complex) and same anatomic category (trunk), the lengths are added together and reported as a single code
- Wounds repaired under different complexity levels (simple vs. complex) are reported separately and not combined
- Wounds in different anatomic categories are reported separately even if the same complexity
Example: Two complex lacerations on the abdomen — 1.2 cm and 1.0 cm — are combined for a total of 2.2 cm, billed as 13100 (1.1-2.5 cm).
💊 wRVU & Reimbursement
| Component | Value |
|---|---|
| Work RVU (wRVU) | 3.15 |
| Global Period | 90 days |
| Pre-op Period | 1 day |
| Post-op Visits included | Yes (90-day global) |
| Assistant at Surgery | ❌ Generally not payable |
| Co-surgeon | ❌ Not applicable |
| Team Surgery | ❌ Not applicable |
⚠️ Assistant payable status varies by payer. Medicare generally does not allow an assistant surgeon for this procedure. Verify with individual payer policies and use modifier 80, 81, or 82 only when payer policy supports it.
➕ Add-On Code: 13102
When the total complex repair of the trunk exceeds 2.5 cm, report:
| Code | Description |
|---|---|
| 13100 | Primary code — first 1.1 cm to 2.5 cm |
| 13101 | Use instead of 13100 when wound is 2.6 cm to 7.5 cm |
| +13102 | Add-on — each additional 1.1 cm to 2.5 cm beyond what 13101 captures |
+13102 is only reportable in addition to 13100 or 13101. It cannot be reported alone.
Example:
A complex trunk repair measuring 10.2 cm total:
→ 13101 (2.6-7.5 cm) + +13102 × 2 (covering the additional 2.7 cm beyond 7.5 cm, reported twice for 1.1-2.5 cm each)
📊 Code Tree — Repair (Closure) Overview
### Simple Repair
[[12001]] - Simple, scalp/neck/axillae/ext/trunk; 2.5 cm or less
[[12002]] - Simple, scalp/neck/axillae/ext/trunk; 2.6-7.5 cm
[[12004]] - Simple, scalp/neck/axillae/ext/trunk; 7.6-12.5 cm
[[12005]] - Simple, scalp/neck/axillae/ext/trunk; 12.6-20.0 cm
[[12006]] - Simple, scalp/neck/axillae/ext/trunk; 20.1-30.0 cm
[[12007]] - Simple, scalp/neck/axillae/ext/trunk; over 30.0 cm
### Intermediate Repair
[[12031]] - Intermediate, scalp/axillae/trunk/ext; 2.5 cm or less
[[12032]] - Intermediate, scalp/axillae/trunk/ext; 2.6-7.5 cm
[[12034]] - Intermediate, scalp/axillae/trunk/ext; 7.6-12.5 cm
[[12035]] - Intermediate, scalp/axillae/trunk/ext; 12.6-20.0 cm
[[12036]] - Intermediate, scalp/axillae/trunk/ext; 20.1-30.0 cm
[[12037]] - Intermediate, scalp/axillae/trunk/ext; over 30.0 cm
### Complex Repair — Trunk ⬅️ YOU ARE HERE
**[[13100]]** - Complex, trunk; **1.1-2.5 cm** ✅
[[13101]] - Complex, trunk; 2.6-7.5 cm
[[+13102]] - Complex, trunk; each additional 1.1-2.5 cm (add-on)
### Complex Repair — Scalp, Arms, Legs
[[13120]] - Complex, scalp/arms/legs; 1.1-2.5 cm
[[13121]] - Complex, scalp/arms/legs; 2.6-7.5 cm
[[+13122]] - Complex, scalp/arms/legs; each additional 1.1-2.5 cm (add-on)
### Complex Repair — Face/Neck/Hands/Feet/Genitalia
[[13131]] - Complex, forehead/cheeks/chin/mouth/neck/axillae/genitalia/hands/feet; 1.1-2.5 cm
[[13132]] - Complex, same sites; 2.6-7.5 cm
[[+13133]] - Complex, same sites; each additional 1.1-2.5 cm (add-on)
### Complex Repair — Eyelids/Nose/Ears/Lips
[[13150]] - Complex, eyelids/nose/ears/lips; 1.0 cm or less
[[13151]] - Complex, eyelids/nose/ears/lips; 1.1-2.5 cm
[[13152]] - Complex, eyelids/nose/ears/lips; 2.6-7.5 cm
[[+13153]] - Complex, eyelids/nose/ears/lips; each additional 1.1-2.5 cm (add-on)
✅ Includes
- Complex wound repair requiring more than layered closure
- Scar revision with complex closure
- Debridement of traumatic lacerations or avulsions with complex closure
- Extensive undermining of wound edges
- Placement of stents or bolsters
- Retention suture placement
- All suture material (absorbable and non-absorbable) used in the repair
- Local anesthesia administration
- Wound irrigation
- Hemostasis (e.g., electrocautery used during repair)
- Simple ligation of small vessels encountered during repair
❌ Excludes / Do Not Report With
| Excluded Code/Scenario | Reason / Correct Action |
|---|---|
| 12001-12021 (Simple repair) | Do not report simple repair if complex technique is used |
| 12031-12057 (Intermediate) | Do not report intermediate repair when complex criteria are met |
| 97597/97598 (Active wound care debridement) | Do not separately bill debridement when it is performed as part of complex closure |
| 11040-11047 (Debridement) | Debridement is bundled into complex repair when performed at same encounter for same wound |
| 15002-15278 (Skin grafts) | When a graft or flap is required, those codes replace repair codes |
| 13101 or 13120 etc. | Do not combine with another complex repair code from a different anatomic group unless the wounds are in different anatomic categories |
| Wound closure strips only | Not reportable as repair — no suturing involved |
🔁 Common Modifiers Used With 13100
| Modifier | Description |
|---|---|
| 51 | Multiple procedures — append to secondary procedures in same session |
| 59 | Distinct procedural service — use when payer bundles 13100 with another procedure incorrectly |
| XS | Separate structure (NCCI preferred alternative to 59 in some contexts) |
| 79 | Unrelated procedure during postoperative period of another global surgery |
| 78 | Return to OR for complication during global period |
| 58 | Staged or related procedure during global period |
| 80 | Assistant surgeon (verify payer policy — generally not covered) |
| RT / LT | Right/Left — rarely applicable to trunk but may be used by some payers |
🏥 MS-DRG Considerations (Inpatient)
13100 is a surgical CPT code used primarily in the outpatient or ED setting. When performed in the inpatient setting, it is coded via ICD-10-PCS rather than CPT. However, the following are relevant for inpatient coders:
- Complex repairs of the trunk in the inpatient setting are typically reported with ICD-10-PCS root operation: Repair (root operation value = Q) under the Skin and Breast body system (character: H).
- Whether the procedure is considered an OR procedure affects MS-DRG assignment — complex skin repairs generally do trigger an OR-based DRG.
- DRGs that may be impacted include:
| MS-DRG | Description |
|---|---|
| 573 | Skin Graft &/or Debridement w MCC |
| 574 | Skin Graft &/or Debridement w CC |
| 575 | Skin Graft &/or Debridement w/o CC/MCC |
| 579 | Other Skin, Subcut Tis & Breast Proc w MCC |
| 580 | Other Skin, Subcut Tis & Breast Proc w CC |
| 581 | Other Skin, Subcut Tis & Breast Proc w/o CC/MCC |
⚠️ Always verify MS-DRG impact using your facility’s grouper. DRG assignment is driven by the principal diagnosis, CC/MCC status, and ICD-10-PCS procedure codes — not CPT codes in the inpatient setting.
🧾 Common ICD-10-CM Diagnosis Codes Used With 13100
Note: HCC = Hierarchical Condition Category (CMS-HCC Risk Adjustment Model relevance). Most traumatic wound codes do not carry HCC weight. Chronic wound and underlying systemic disease codes may.
| ICD-10-CM Code | Description | HCC |
|---|---|---|
| S21.001A | Unspecified open wound, right front thorax wall w/o penetration, initial | ❌ |
| S21.002A | Unspecified open wound, left front thorax wall w/o penetration, initial | ❌ |
| S21.101A | Unspecified open wound, right back thorax wall w/o penetration, initial | ❌ |
| S31.000A | Unspecified open wound, lower back/pelvis w/o retroperitoneal penetration, init | ❌ |
| S31.100A | Unspecified open wound of abdominal wall, unspecified quadrant, init | ❌ |
| S31.119A | Laceration w/o foreign body of abdominal wall, unspecified site, init | ❌ |
| S31.129A | Laceration w/foreign body of abdominal wall, unspecified site, init | ❌ |
| L89.310 | Pressure ulcer of right buttock, unstageable | ✅ HCC 161 |
| L89.320 | Pressure ulcer of left buttock, unstageable | ✅ HCC 161 |
| L97.419 | Non-pressure chronic ulcer, right buttock, unspecified severity | ✅ HCC 161 |
| T79.3XXA | Post-traumatic wound infection, initial encounter | ❌ |
| L76.31 | Accidental puncture/laceration of skin during a procedure | ❌ |
| T81.31XA | Disruption of internal operation wound, NEC, initial encounter | ❌ |
| T81.32XA | Disruption of external operation wound, NEC, initial encounter | ❌ |
| E11.621 | Type 2 DM with foot ulcer (document if DM complicates wound healing) | ✅ HCC 18 |
| L03.311 | Cellulitis of abdominal wall | ❌ |
📌 When the wound results from trauma, use the most specific S-code with the appropriate 7th character:
- A = Initial encounter (active treatment)
- D = Subsequent encounter (routine care)
- S = Sequela
💡 Coding Examples
Example 1 — Traumatic Laceration with Debridement
Clinical scenario: A patient presents to the ED with a 2.0 cm jagged laceration of the anterior abdominal wall after a fall onto a metal fence post. The wound has contaminated and devitalized tissue. The physician debrides the wound edges and performs a layered closure with retention sutures.
Correct coding:
- 13100 — Complex repair, trunk, 2.0 cm
- S31.119A — Laceration w/o foreign body, abdominal wall, initial encounter
- W17.89XA — Other fall from one level to another, initial encounter
✅ Complex repair is appropriate because debridement and retention sutures were used.
Example 2 — Scar Revision with Complex Closure
Clinical scenario: A patient undergoes elective scar revision on the back. An old hypertrophic scar (1.5 cm) is excised, wound edges are freshened, and extensive undermining is performed bilaterally to allow tension-free layered closure.
Correct coding:
✅ Both scar revision and extensive undermining independently justify complex repair coding.
Example 3 — Multiple Wounds, Combined Length
Clinical scenario: A patient has two complex lacerations on the chest — one is 1.2 cm and one is 0.9 cm. Both wounds are on the trunk, both require extensive undermining for closure.
Correct coding:
- 13100 — Combined length = 2.1 cm (wounds added: 1.2 + 0.9 = 2.1 cm falls within 1.1-2.5 cm range)
✅ Wounds of the same complexity and same anatomic category are summed, not billed separately.
Example 4 — Complex Trunk + Complex Face (Same Session)
Clinical scenario: Same operative session — complex repair of a 2.0 cm chest wound AND a complex repair of a 1.5 cm chin laceration.
Correct coding:
- 13100 — Complex, trunk, 2.0 cm
- 13131 - 51 — Complex, chin, 1.5 cm (modifier 51 for multiple procedures)
✅ Different anatomic categories are billed separately. Modifier 51 appended to the secondary procedure.
Example 5 — Complex Repair Should NOT Be Reported (Layered Closure Only)
Clinical scenario: A clean surgical incision on the abdomen is closed in layers (subcutaneous + dermal + subcuticular) after an open appendectomy.
Correct coding:
- Closure is bundled into the primary surgical procedure (44950, 44960)
- 13100 would be incorrect — do not separately report wound closure that is integral to a primary surgical procedure
⚠️ Common Coding Pitfalls
- Upcoding simple/intermediate repairs to complex: Documentation must clearly support one of the complex repair elements. Layered closure alone = intermediate, not complex.
- Failing to combine wound lengths: Multiple wounds in the same category and site must be added — billing separately inflates reimbursement and triggers audits.
- Reporting debridement separately: 97597/97598 or 11042-11047 are bundled when done as part of the complex closure at the same encounter.
- Using 13100 inpatient: In the inpatient setting, ICD-10-PCS is required. CPT 13100 is for outpatient/professional fee coding.
- Ignoring the global period: During the 90-day global period, follow-up wound care visits are bundled. Separate E&M or wound care codes require modifier 24 or 79 if truly unrelated.
🔗 Related Codes Quick Reference
| Code | Description |
|---|---|
| 12001 | Simple repair, trunk/ext, 2.5 cm or less |
| 12031 | Intermediate repair, trunk/ext, 2.5 cm or less |
| 13101 | Complex repair, trunk, 2.6-7.5 cm |
| +13102 | Complex repair, trunk, each add’l 1.1-2.5 cm |
| 13120 | Complex repair, scalp/arms/legs, 1.1-2.5 cm |
| 13131 | Complex repair, face/neck/hands/feet, 1.1-2.5 cm |
| 97597 | Active wound care debridement ≤ 20 cm² |
| 11042 | Debridement, subcutaneous tissue; 20 cm² or less |
| 15002 | Surgical prep/creation of recipient site, trunk/arms/legs; first 100 cm² |
| 15100 | Split-thickness autograft, trunk/arms/legs; first 100 cm² |
| 15570 | Pedicle flap, trunk |
AMA CPT® Professional Edition 2026 | CMS Physician Fee Schedule 2026 | CMS NCCI Policy Manual | CMS ICD-10-CM Official Guidelines for Coding and Reporting FY2026 | CMS MS-DRG Definitions Manual v43