18.1 CPT Coding, Modifiers & Documentation for Debridement and Biologics

18.1 CPT Coding, Modifiers & Documentation for Debridement and Biologics

Core Clinical Principle: Procedural coding in advanced wound care is governed strictly by anatomical depth of excised tissue, documented surface area summation, and demonstrable medical necessity. Misinterpreting exposed wound bed structures as excised tissue, unbundling multiple base codes at identical depths, neglecting anatomical boundaries for CTP application codes, or inappropriately appending modifier -25 represents high-risk compliance failures subject to federal False Claims Act scrutiny and Medicare recovery audits.

Physician procedural reimbursement in wound care demands rigorous alignment between operative technique, anatomical pathology, and Current Procedural Terminology (CPT) guidelines. For the Certified Wound Specialist Physician (CWSP), documentation serves a dual mandate: establishing an evidence-based clinical record of healing trajectory and providing an audit-proof medico-legal defense under Medicare Administrative Contractor (MAC) Local Coverage Determinations (LCDs).

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1. Procedural Coding, Regulatory Framework & Audit Scrutiny

Clinical wound care documentation exists under an aggressive federal regulatory umbrella. The statutory foundation of Medicare reimbursement rests upon Section 1862(a)(1)(A) of the Social Security Act, which mandates that no payment may be made for services that "are not reasonable and necessary for the diagnosis or treatment of illness or injury."

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|                        FEDERAL REGULATORY & ENFORCEMENT ARSENAL                                 |
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| 1. FALSE CLAIMS ACT (31 U.S.C. §§ 3729–3733)                                                    |
|    • Imposes civil liability on individuals who knowingly present or cause to be presented a     |
|      false or fraudulent claim for payment to the federal government.                           |
|    • "Knowing" encompasses actual knowledge, deliberate ignorance, or reckless disregard.        |
|    • Penalties: Substantial per-claim statutory penalties plus treble (3x) actual damages.     |
|    • Common wound care triggers: Systematic upcoding to deeper tissue layers (e.g., billing      |
|      bone debridement 11044 when bone was only visualized), phantom debridements, unbundling.   |
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| 2. CIVIL MONETARY PENALTIES LAW (CMPL, 42 U.S.C. § 1320a-7a)                                   |
|    • Authorizes HHS Office of Inspector General (OIG) to impose administrative penalties and     |
|      assessments against providers submitting claims for services not provided as claimed.      |
|    • Enforces potential administrative exclusion from Medicare, Medicaid, and all federal health|
|      care programs.                                                                             |
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| 3. THIRD-PARTY AUDIT ENTITIES & CONTRACTORS                                                     |
|    • Recovery Audit Contractors (RACs): Fee-for-service contingency contractors identifying      |
|      improper post-payment overpayments and underpayments.                                      |
|    • Unified Program Integrity Contractors (UPICs): Identify, investigate, and deter fraud,     |
|      waste, and abuse; conduct pre-payment and post-payment audits; issue payment suspensions.  |
|    • Medicare Administrative Contractors (MACs): Jurisdiction-specific contractors establishing |
|      Local Coverage Determinations (LCDs) and Local Coverage Articles (LCAs) detailing medical   |
|      necessity criteria, coverage frequency limitations, and non-negotiable documentation.      |
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2. Active Wound Care Management vs. Surgical Excisional Debridement

CPT codes for wound debridement are divided into two distinct regulatory domains based on the nature of tissue removal and the anatomical layer excised:

1. Active Wound Care Management (CPT 97597–97602): Non-excisional or selective debridement limited to the superficial epidermis and dermis without cutting into viable subcutaneous architecture.
2. Surgical Excisional Debridement (CPT 11042–11047): Open, sharp excisional removal of nonviable tissue extending into or through subcutaneous tissue, muscle, fascia, or bone.

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|                       PROCEDURAL DEBRIDEMENT CODING DOMAINS                                     |
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| 1. SELECTIVE DEBRIDEMENT (Active Wound Care Management: 97597, 97598)                          |
|    • Anatomical Depth: Epidermis and/or Dermis ONLY (never extends into subcutaneous fat)       |
|    • Pathological Targets: Devitalized epidermis/dermis, fibrinous slough, biofilm, exudate     |
|    • Surgical Instruments: Scalpel, curette, scissors, hydrosurgery (Versajet), ultrasound      |
|    • Billing Units: 97597 (first 20 cm² or less); 97598 (each additional 20 cm² or fraction)   |
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| 2. SURGICAL EXCISIONAL DEBRIDEMENT (Surgery / Integumentary: 11042 - 11047)                     |
|    • Stratified strictly by DEEPEST TISSUE LAYER EXCISED (not exposed floor)                    |
|    • Subcutaneous Tissue: 11042 (first 20 cm² or less); 11045 (each additional 20 cm²)         |
|    • Fascia and/or Muscle: 11043 (first 20 cm² or less); 11046 (each additional 20 cm²)       |
|    • Bone (Osseous cortex/marrow): 11044 (first 20 cm² or less); 11047 (each additional 20 cm²)|
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CPT 97597 & 97598: Selective Active Wound Care Management

• CPT 97597: Debridement (e.g., high pressure waterjet with/without suction, sharp selective debridement with scissors, scalpel and forceps), open wound, (e.g., fibrin, devitalized epidermis and/or dermis, exudate, debris, biofilm), including topical application(s), wound assessment, use of a whirlpool, when performed and instruction(s) for ongoing care, per session, total wound(s) surface area; first 20 sq cm or less.
• CPT 97598: Total wound(s) surface area; each additional 20 sq cm, or part thereof (List separately in addition to code for primary procedure).

Clinical Scope & Permissible Modalities:

• Gentle scraping with a dermal curette or dermal scissors to strip away nonviable fibrin, slough, or bacterial biofilm down to the dermal layer.
• High-pressure waterjet hydrosurgery (e.g., Versajet) calibrated to ablate superficial debris and biofilm while preserving dermal collagen.
• Low-frequency contact or non-contact ultrasound debridement (e.g., Sonoca, MIST therapy) used to cavitate and fragment nonviable superficial proteins.
• Note on CPT 97602: Represents non-selective debridement (e.g., wet-to-moist dressings, enzymatic debriding agents such as collagenase Santyl, chemical debridement, or mechanical whirlpool). CPT 97602 is billed per session regardless of wound size and is not reimbursed separately under many physician fee schedules (often bundled into facility fees).

Comparative Matrix: Selective vs. Surgical Excisional Debridement

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3. CPT Surgical Debridement Codes (11042–11047) Stratification

Surgical debridement codes reside in the Surgery / Integumentary System section of the CPT manual. They mandate true excisional debridement—the physical removal of nonviable tissue using surgical cutting instruments (scalpel blade, sharp curette, surgical scissors, bone rongeur) carried down to viable tissue margins.

CPT SURGICAL DEBRIDEMENT CODES (11042 - 11047)
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SUBCUTANEOUS TISSUE (Fat / Adipose):
  • 11042 : Debridement, subcutaneous tissue (includes epidermis and dermis,
            if performed); first 20 sq cm or less.
  • 11045 : Each additional 20 sq cm, or part thereof (Add-on to 11042).

MUSCLE AND/OR FASCIA (Deep investing fascia, tendon sheath, muscle belly):
  • 11043 : Debridement, muscle and/or fascia (includes epidermis, dermis,
            and subcutaneous tissue, if performed); first 20 sq cm or less.
  • 11046 : Each additional 20 sq cm, or part thereof (Add-on to 11043).

BONE (Cortical excision, osteotomy, bone curettage, marrow sampling):
  • 11044 : Debridement, bone (includes epidermis, dermis, subcutaneous tissue,
            muscle and/or fascia, if performed); first 20 sq cm or less.
  • 11047 : Each additional 20 sq cm, or part thereof (Add-on to 11044).
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Critical Coding Rules & The "Deepest Layer Excised" Mandate

A core coding rule for debridement is:

The Cardinal Depth Mandate: CPT surgical debridement is coded strictly according to the deepest tissue layer actually excised and debrided, NEVER according to the baseline depth of the wound or the tissue visible at the ulcer base before or after the procedure!

The "Probe-to-Bone" Clinical Trap

Consider a patient with a chronic Stage 4 sacral pressure injury where cortical sacral bone is clearly visible and palpated with a sterile metal probe at the ulcer floor. The physician sharp-debrides 15 cm² of necrotic, liquefied subcutaneous adipose tissue from the undermining margins and curettes fibrinous debris from the fascia, but does not scrape, drill, or rongeur the bone.

• Incorrect Coding: Submitting CPT 11044 (bone debridement) because bone is "exposed" or "involved" in the wound.
• Correct Coding: Submitting CPT 11042 (subcutaneous tissue) or 11043 (fascia/muscle), depending on the deepest tissue actually cut and excised. Coding 11044 without documented excision of nonviable osseous tissue is classified as fraudulent upcoding under federal audits.

The "Exposed Tendon / Fascia" Trap

Similarly, if an Achilles tendon or dorsal extensor tendon is visible in a foot ulcer, but the clinician only sharp-debrides hyperkeratotic epidermal margins and necrotic subcutaneous fat without debriding the tendon or paratenon, the service must be coded as 11042, not 11043. The operative note must explicitly document the excision of fascial or tendinous fibers to justify 11043.

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4. The NCCI Surface Area Summation Rule & Multi-Wound Aggregation

CMS National Correct Coding Initiative (NCCI) policy and MAC Local Coverage Determinations enforce strict aggregation formulas when a patient presents with multiple ulcerations treated during the same clinical encounter.

The 5-Step Summation Algorithm

1. Group by Anatomical Depth: Separate all debrided wounds into cohorts based on the deepest tissue layer excised (Cohort A: Subcutaneous; Cohort B: Muscle/Fascia; Cohort C: Bone).
2. Sum Surface Areas within Each Cohort: Add the pre-debridement surface areas (Length × Width in cm²) of all wounds within the identical depth cohort.
3. Assign One Primary Base Code per Depth: Report exactly one base code (11042, 11043, or 11044) for the first 20 cm² of total aggregated surface area for that specific depth.
4. Assign Add-on Units for Excess Area: For each additional 20 cm² (or fraction thereof) beyond the initial 20 cm² within that same depth cohort, bill the corresponding add-on code (11045, 11046, or 11047).
5. Never Bill Multiple Base Codes for the Same Depth: Submitting 11042 twice on the same claim for two separate wounds debrided to the subcutaneous level is an immediate NCCI unbundling violation and will result in claim denial or audit recoupment.

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|                        SURFACE AREA SUMMATION CLINICAL EXAMPLES                                 |
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| CASE 1: MULTIPLE WOUNDS AT THE SAME TISSUE DEPTH                                                |
| • Wound 1 (Right Trochanter): 14 cm² debrided to SUBCUTANEOUS tissue                            |
| • Wound 2 (Left Ischium): 12 cm² debrided to SUBCUTANEOUS tissue                                |
| • Calculation: Total Subcutaneous Area = 14 cm² + 12 cm² = 26 cm²                               |
|   - First 20 cm²: CPT 11042 (Base code) x 1 unit                                                |
|   - Remaining 6 cm²: CPT 11045 (Add-on code: each additional 20 cm² or part thereof) x 1 unit   |
| • CORRECT BILLING: 11042 x 1, 11045 x 1                                                         |
| • AUDIT TRAP: Billing 11042 x 2 (Unbundling violation!)                                         |
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| CASE 2: MULTIPLE WOUNDS AT DIFFERENT TISSUE DEPTHS                                              |
| • Wound 1 (Right Calcaneus): 8 cm² debrided to BONE (cortical curettage)                        |
| • Wound 2 (Right Lateral Malleolus): 15 cm² debrided to SUBCUTANEOUS tissue                     |
| • Calculation:                                                                                  |
|   - Bone Cohort (8 cm²): CPT 11044 x 1 unit (Base code for bone <= 20 cm²)                      |
|   - Subcutaneous Cohort (15 cm²): CPT 11042 x 1 unit (Base code for subcutaneous <= 20 cm²)    |
| • CORRECT BILLING: 11044 (Primary, higher RVU), 11042-59 (or 11042-XS)                          |
| • Modifiers: Append Modifier -59 (Distinct Procedural Service) or -XS (Separate Structure)      |
|   to 11042 to unbundle from the deeper procedure per NCCI guidelines.                          |
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5. Mandatory Operative Documentation Elements for Audit Defense

To survive Medicare RAC, UPIC, or commercial payer pre-payment and post-payment audits, the medical record must explicitly contain the following seven elements for every debridement procedure:

1. Pre-Debridement Dimensions: Exact length, width, and depth in centimeters or millimeters measured prior to tissue excision.
2. Tissue Characteristics & Viability: Precise percentage and description of nonviable material (e.g., "60% firm, adherent black eschar; 40% devitalized yellow-gray fibrinous slough; moderate purulent exudate").
3. Instruments Utilized: Specific surgical cutting tools employed (e.g., "#15 scalpel blade, 4 mm dermal curette, Metzenbaum scissors, 3 mm bone rongeur").
4. Explicit Deepest Layer Excised: Specific anatomical tissue layer cut and removed (e.g., "Sharp excisional debridement was carried down through nonviable subcutaneous adipose tissue to the level of bleeding, viable subcutaneous fat"). Vague terms such as "wound was cleaned" or "slough was removed" trigger automatic debridement downcoding to 97597 or complete denial.
5. Post-Debridement Dimensions & Bed Appearance: Post-procedure measurements and appearance (e.g., "Post-debridement ulcer measured 4.2 × 3.1 × 0.6 cm with a clean, 100% viable bleeding base; no residual necrotic tissue").
6. Hemostasis Method & Estimated Blood Loss: Modality used to achieve hemostasis (e.g., "Hemostasis achieved via direct pressure and application of silver nitrate cautery; minimal blood loss (<5 mL)").
7. Patient Tolerance & Anesthetic Technique: Type and volume of local anesthetic administered (e.g., "Local field infiltration with 5 mL of 1% lidocaine with sodium bicarbonate buffer; patient tolerated procedure without complication").

AUDIT TRIGGER WORDS (AUTOMATIC DOWNCODING)   AUDIT DEFENSE TERMINOLOGY (COMPLIANT)
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• "Wound was debrided and cleaned"         • "Sharp excisional debridement carried
                                              through necrotic adipose to viable fat"
• "Slough was curetted away"               • "4 mm dermal curette used to excise
                                              avascular fascia until punctate bleeding"
• "Callus was pared down"                  • "Hyperkeratotic margin saucerized using
                                              #15 scalpel blade to level of dermis"
• "Necrotic bone was addressed"            • "Bone rongeur utilized to excise 4 mm
                                              of necrotic cortical bone to bleeding marrow"
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6. Evaluation & Management (E/M) Coding & Modifier -25

Modifier -25 is defined in the CPT manual as:

Modifier -25: Significant, Separately Identifiable Evaluation and Management Service by the Same Physician or Other Qualified Health Care Professional on the Same Day of the Procedure or Other Service.

Because minor surgical procedures (such as CPT 11042–11047) inherently include routine pre-procedural examination, the decision to perform the procedure, local anesthesia administration, and standard post-procedural dressing application, the routine evaluation of the wound itself is already bundled into the surgical reimbursement.

INHERENT PROCEDURE CARE (BUNDLED)        SEPARATELY IDENTIFIABLE E/M (-25 ELIGIBLE)
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• Inspecting the target wound             • Diagnosing new, distinct problem (e.g., cellulitis)
• Measuring dimensions & depth            • Acute change in systemic status (e.g., sepsis)
• Deciding to debride that day            • Comprehensive comorbidity review (glycemia, PAD)
• Obtaining informed consent              • Ordering diagnostic tests (Doppler, MRI, labs)
• Infiltrating local anesthetic           • Initiating new systemic therapy (IV/oral antibiotics)
• Applying primary wound dressing         • Total revision of global care plan & offloading
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Medical Decision Making (MDM) Criteria for Modifier -25

Under the AMA/CMS 2021/2023 E/M guidelines, scoring an outpatient visit (CPT 99202–99215) requires satisfying at least 2 out of 3 MDM categories:

1. Number and Complexity of Problems Addressed: Minimal, Low, Moderate (e.g., 1 chronic illness with severe exacerbation, or 2 stable chronic illnesses), or High (e.g., acute limb- or life-threatening illness).
2. Amount and/or Complexity of Data to be Reviewed and Analyzed: Review of external notes, ordering unique tests (e.g., duplex ultrasound, plain radiographs), independent interpretation of imaging, or discussion with external specialists.
3. Risk of Complications and/or Morbidity or Mortality of Patient Management: Low (over-the-counter dressings), Moderate (prescription drug management, decision regarding minor surgery with identified risk factors), or High (decision regarding urgent major surgery or hospitalization).

Audit Defense Strategy for Modifier -25

To prevent denial of the E/M code during payer audits:

• Document Distinct Sections: Maintain a physically separate "E/M Progress Note" detailing history, systemic review of systems, physical exam, and MDM, completely separated from the "Surgical Debridement Procedure Note."
• Distinct Medical Necessity: The E/M portion must address systemic complexities (e.g., uncontrolled hyperglycemia impairing healing, acute ascending bacterial lymphangitis requiring prescription oral fluoroquinolones, or ordering an urgent arterial duplex to evaluate critical limb ischemia).
• Diagnosis Coding Alignment: While not strictly required by CPT, linking the E/M code to an underlying systemic diagnosis (e.g., E11.621, Type 2 diabetes with foot ulcer) and the debridement code to the ulcer site (e.g., L97.511, non-pressure ulcer of right foot) establishes clear clinical demarcation.

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7. Global Surgical Package Concepts & Payer Policies

The Global Surgical Package encompasses all standard services provided by the operating physician before, during, and after a surgical procedure:

GLOBAL SURGICAL PERIOD CLASSIFICATIONS
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0-Day Global Period (Minor Surgery; e.g., CPT 11042 - 11047 under MPFS):
  • Pre-procedure care on the day of the procedure.
  • Intra-procedure services (anesthesia, excision, hemostasis).
  • Post-procedure care on the SAME DAY of the procedure only.
  • Visits on Day 1, Day 2, etc., are SEPARATELY BILLABLE if medically necessary!

10-Day Global Period (Minor Surgery; select commercial / Medicaid payers):
  • Includes the day of surgery plus the subsequent 10 calendar days.
  • Post-procedure visits and routine dressing changes within 10 days are BUNDLED.
  • Unrelated E/M during global period requires Modifier -24.
  • Staged/related procedure during global period requires Modifier -58 or -79.

90-Day Global Period (Major Surgery; e.g., major amputations, muscle flaps):
  • 1 day pre-operative, day of surgery, and 90 postoperative days included.
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Postoperative Dressing Changes & Incident-To Clinic Care

Routine postoperative dressing changes performed in an outpatient clinic without active debridement do not qualify for surgical CPT codes. If a patient returns for a dressing change:

• If no debridement is performed and no physician-level E/M is delivered, the service is either unbillable (facility fee only) or billed as a low-level nurse visit (CPT 99211, "incident-to" under direct physician supervision).
• Dressing materials used in the office are generally non-reimbursable separately under Medicare Part B (packaged into the practice expense RVU of the visit).

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8. Cellular and/or Tissue-Based Products (CTPs): Billing, Coding & Application

Cellular and/or Tissue-Based Products (CTPs, historically termed skin substitutes) play an advanced role in non-healing diabetic foot ulcers and venous leg ulcers. Reimbursement mandates precise reporting of both the procedural application code (CPT 15271–15278) and the biologic product code (HCPCS Level II Q-codes), alongside strict adherence to wastage documentation.

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|                        CTP / SKIN SUBSTITUTE DUAL REIMBURSEMENT ARCHITECTURE                    |
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| COMPONENT 1: PROCEDURAL APPLICATION (CPT 15271 - 15278)                                         |
| • Stratified by Anatomical Site: Group 1 (Trunk/Arms/Legs) vs Group 2 (Feet/Hands/Face/Digits)   |
| • Stratified by Total Surface Area: Small (< 100 cm²) vs Large (>= 100 cm²)                     |
| • Add-on units capture surface area beyond base increments                                      |
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| COMPONENT 2: BIOLOGICAL PRODUCT SUPPLY (HCPCS Level II Q-Codes: Q4100 - Q4299)                  |
| • Billed per square centimeter (cm²) based on package label dimensions                         |
| • Examples: Q4101 (Apligraf), Q4106 (Dermagraft), Q4116 (AlloDerm), Q4121 (Theraskin),          |
|   Q4154 (Biovance), Q4186 (Epifix)                                                              |
| • Wastage Reporting Through 2025: Modifier -JW (discarded) vs Modifier -JZ (zero waste)         |
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CPT Application Codes (15271–15278) Classification Matrix

Critical Coding Distinction: Application of a CTP to a plantar foot ulcer or dorsal toe ulcer must never be coded as 15271; the foot and digits are strictly classified under CPT 15275–15278.

Surgical Site Preparation vs. Debridement with CTPs

Under CPT and NCCI rules:

• Surgical preparation of the recipient site (CPT 15002–15005) creates a fresh, surgical wound bed by excising gross scar tissue, granulations, or nonviable dermis. When performed on the same anatomical site, routine surgical debridement (11042–11047) is bundled into the CTP application code (15271–15278) and cannot be separately unbundled on the same ulcer on the same day.
• If a patient has two distinct wounds—one receiving a CTP and a separate wound undergoing surgical excisional debridement—the debridement may be billed with Modifier -59 or -XS appended.

Wastage Reporting for Single-Use Products: Modifiers -JW & -JZ

CTPs are supplied in single-use packages with fixed dimensions, so trimming often creates waste. Through 2025, when skin substitutes were billed as separately payable biologicals, Medicare required the JW modifier for discarded amounts and the JZ modifier when nothing was discarded. With the CY2026 reclassification of skin substitutes as incident-to supplies in the physician office, confirm your MAC's current reporting instructions before applying these rules.

CMS SINGLE-DOSE WASTAGE MODIFIERS (APPLIED TO SKIN SUBSTITUTES THROUGH 2025)
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MODIFIER -JW (Drug / Biologic Discarded):
  • Reports the amount of product discarded and not administered to any patient.
  • Billed on a separate claim line following the administered product line.
  • Documentation must record: total package size, exact amount applied, exact amount
    wasted, lot number, serial number, expiration date, and disposal protocol.

MODIFIER -JZ (Zero Drug / Biologic Discarded):
  • CMS modifier indicating that no product was discarded (100% applied).
  • When required, claims for single-dose products missing JW or JZ can be returned
    or denied.
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Clinical Calculation Example: A physician treats an 18 cm² chronic diabetic foot ulcer with an advanced living cryopreserved skin substitute supplied as a 37.5 cm² piece (HCPCS Q4106, 1 unit = 1 cm²), billed under the pre-2026 rules. The physician trims 18 cm² to cover the ulcer and discards the remaining 19.5 cm²:

• Line 1: CPT 15275 (Application, foot; first 25 cm²) × 1 unit
• Line 2: HCPCS Q4106 (Dermagraft administered) × 18 units
• Line 3: HCPCS Q4106-JW (Dermagraft discarded/wasted) × 19.5 units

Hospital Outpatient Prospective Payment System (HOPPS) Packaging

Through CY2025, hospital outpatient departments (HOPDs) and ambulatory surgery centers (ASCs) packaged skin substitute payment into the application procedure under high-cost and low-cost groupings; payment policy was revised for CY2026, so verify the current rules:

• High-Cost CTP Package: Products exceeding the established mean unit cost (MUC) threshold are mapped to high-paying application APCs.
• Low-Cost CTP Package: Products priced below the threshold are mapped to lower-paying APCs. Using a high-cost CTP when packaged under a low-cost APC creates significant institutional financial loss.

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9. Local Coverage Determinations, 4-Week Trial & ABN Protocols

Under Section 1862(a)(1) of the Social Security Act, Medicare Part B will only pay for services deemed "reasonable and necessary". When a wound care physician provides an advanced modality that is usually covered but is anticipated to be denied in a specific instance due to unmet LCD criteria, the physician must execute an Advance Beneficiary Notice of Noncoverage (ABN, Form CMS-R-131).

Local Coverage Policies and the Standard-of-Care Trial

Skin substitute coverage is set by each Medicare Administrative Contractor (MAC). The multi-MAC skin substitute LCDs finalized in 2024 were withdrawn in December 2025 before their January 1, 2026 effective date, so legacy local policies apply where they exist. These policies typically require:

• At least 4 weeks of documented standard care without adequate healing (the withdrawn LCDs used less than 50% area reduction for diabetic foot ulcers), including debridement, offloading for diabetic foot ulcers, continuous compression for venous leg ulcers, infection control, and moisture management.
• Adequate perfusion and a clean wound bed, with measurements documented before every application.
• Application limits that vary by contractor (for example, the legacy Novitas policy treats more than 10 applications to one wound within 12 weeks as not reasonable and necessary).
• ABN requirement: If a service is expected to be denied as not reasonable and necessary (for example, applying a product before the required trial), a valid, signed ABN must be obtained before the procedure to bill the patient.

HCPCS ABN Modifiers Matrix