DraftUnitedHealthcarePolicy CS157TN.J

Negative Pressure Wound Therapy (for Tennessee Only)

Policy governing use of NPWT for Tennessee Medicaid and CoverKids beneficiaries in outpatient settings and upon discharge; defines indications, contraindications, documentation and coding guidance.

Policy Summary

PayerUnitedHealthcare

PolicyNegative Pressure Wound Therapy (for Tennessee Only)

Policy CodePolicy CS157TN.J

Change TypeRevised contraindicationsevidence update

Effective DateJuly 1, 2025

Next Review DateN/A

Key ActionObtain and document a complete wound therapy program and evidence of failure after 30 days before seeking authorization for outpatient NPWT.

SourceLink

POLICY UPDATE CHANGES

Revised list of contraindications to negative pressure wound therapy (NPWT): added 'anticoagulation therapy' and replaced 'uncontrolled soft tissue infection or osteomyelitis within vicinity of wound' with 'uncontrolled soft tissue infection or untreated osteomyelitis within vicinity of wound'.

Updated Clinical Evidence and References sections to reflect the most current information.

30 daysmin conventional tx before NPWT

Stage III/IVpressure ulcer stages

97605-97608CPT codes listed

A6550,A9272,E2402

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07/01/2025policy revision date

1archived prior version

Coverage Criteria for NPWT

Initial Coverage Criteria

Covered when ALL of the following are met for outpatient or discharge NPWT:

Complete wound therapy tried/considered: Documentation of evaluation, care, and wound measurements; application of dressings to maintain a moist wound environment; debridement of necrotic tissue if present; evaluation of and provision for adequate nutritional status; documentation by provider of indication for NPWT; and documentation that the open wound has not responded to conventional treatment after 30 days.30 days

Use this to demonstrate failure of conventional therapy prior to NPWT initiation.

Indication-specific criteria

Pressure ulcer (Stage III or IV): Complete wound therapy as above; appropriate turning/positioning; use of a pressure-reducing support surface; moisture and incontinence management.Stage III or IV
Document stage and supportive measures.
Neuropathic ulcer (e.g., diabetic foot ulcer): Complete wound therapy as above; comprehensive diabetic management program; documented reduction in pressure on the ulcer (offloading).as clinically appropriate
Document glycemic and offloading measures.
Venous insufficiency ulcer: Complete wound therapy as above; compression bandages and/or garments used consistently for at least 30 days; leg elevation and ambulation.≥30 days compression
Document prior compression therapy and response.
Open surgical wound: Post-operative dehiscence OR open non-healing amputation site in diabetics OR post-sternotomy infection (mediastinitis) OR delayed/non-healing of skin graft likely due to irregular contour or inadequate graft bed blood flow; all require documentation of complete wound therapy as above.as noted per sub-condition
Document surgical history and wound characteristics.
High-risk open fracture: Gustilo Grade III open fracture with documentation supporting high-risk status and wound management plan.Gustilo Grade III
Document fracture grade and rationale for NPWT use.

Continuation/Discontinuation Criteria

Discontinuation criteria / treatment failure:

Stop NPWT when: Weekly wound assessments indicate failure of progressive healing (no diminution in surface area or depth within 30 days); OR wound depth is 1 mm or less; OR uniform granulation tissue has been obtained.30 days; 1 mm

Document weekly measurements and clinical rationale for discontinuation.

Evidence summaries by indication

Summarized evidence-based findings by indication (not an authorization algorithm):

Diabetic foot ulcers / neuropathic ulcers: Multiple systematic reviews and meta-analyses report that NPWT may increase healing rates, reduce wound area, increase granulation tissue, and reduce risk of amputation versus moist wound care or standard dressings; evidence quality varies (low to moderate) and higher-quality RCTs are still recommended.

Wang et al., Liu et al., Rys and Cochrane updates summarize benefits with variable certainty.

Venous leg ulcers: Limited evidence suggests NPWT may improve healing in venous ulcers; consider NPWT when first-line compression therapy has failed and to prepare wound for surgical closure.

Hayes report and expert guidance support conditional use after failed compression.

Open surgical wounds / skin grafts / post-sternotomy: Evidence indicates NPWT can reduce some surgical site occurrences and improve split-thickness skin graft take in selected contexts; some RCTs demonstrate benefit while systematic reviews note uncertainty for specific open-abdomen outcomes—consider patient risk factors and wound characteristics.

Coverage for NPWT/NPWTi-d (guideline-aligned)

Covered when ALL of the following are met (per guideline-supported contexts):

General prerequisites: Patient has a wound type for which NPWT is indicated (e.g., postoperative diabetic foot wound, stage III/IV pressure injury, chronic wound failing standard care).

Society guidelines recommend NPWT as adjunctive therapy when standard measures are optimized.

Specific wound contexts: Includes post-operative diabetic foot wounds, stage III/IV pressure injuries, and chronic wounds not progressing with conventional therapy.

IWGDF, NPIAP, WHS, and SVS statements support these contexts.

Prior standard care: For diabetic foot ulcers, failure to demonstrate improvement (>50% wound area reduction) after a minimum of 4 weeks of standard therapy is recommended before adjunctive NPWT.>50% reduction in 4 weeks

Follow SVS/IWGDF guidance on re-evaluation of vascular status, infection control and offloading prior to NPWT.

Evidence strength and limitations

Evidence considerations informing coverage:

Evidence summary: Multiple systematic reviews and meta-analyses suggest NPWTi-d may improve rates of wound closure and reduce complication rates compared with NPWT alone or standard care in heterogeneous wound populations, but evidence quality is low and heterogeneity across studies is high; randomized controlled trials are needed to confirm benefits and determine optimal use and cost-effectiveness.

Interpret NPWTi-d findings cautiously due to small, heterogeneous studies and variable control interventions.

The policy identifies several uses and device types as unproven and not medically necessary because current evidence does not demonstrate sufficient efficacy. Specifically, NPWT is considered not medically necessary for closed surgical incisions and pilonidal disease. In addition, disposable/single-use NPWT systems and NPWT systems with instillation of wound solutions are listed among indications/devices that are unproven and not medically necessary.

Routine use of NPWT — including disposable single-use systems — for closed surgical incisions is not supported by sufficient high-quality evidence to warrant routine coverage; published studies are generally small or at risk of bias and additional prospective, high-quality trials are needed to identify which surgical populations may benefit. Similarly, randomized data for pilonidal disease have not demonstrated superiority of NPWT versus conventional dressings, and current evidence does not support routine NPWT for this indication.

The policy lists specific clinical situations that preclude NPWT. Contraindications include active bleeding or exposed vasculature, presence of eschar or necrotic tissue, exposed bone, nerves, or organs in the wound bed, malignancy in the wound, presence of an open fistula to body organs or cavities within the wound vicinity, and importantly anticoagulation therapy. The policy also excludes use in the setting of uncontrolled soft tissue infection or untreated osteomyelitis within the vicinity of the wound.

The contraindications were revised in the July 1, 2025 policy update to explicitly add anticoagulation therapy and to clarify the infectious exclusion, replacing prior language with uncontrolled soft tissue infection or untreated osteomyelitis within the vicinity of the wound. This operational change is reflected in the policy history and should be considered when assessing medical necessity and prior authorization decisions.

Beyond the revised items above, the policy reiterates other exclusionary conditions that can make NPWT inappropriate, including active bleeding or exposed vasculature, eschar or necrotic tissue present, and exposed bone, nerves, or organs. These clinical conditions increase the risk profile of NPWT and are listed as contraindications to therapy.

Use of NPWT for closed surgical incisions and for pilonidal disease lacks sufficient evidence of safety and effectiveness to support routine coverage. The policy therefore treats these indications as unproven or not medically necessary in most circumstances and requires strong clinical justification and supporting trial evidence for any exception.

Adoption of NPWT with instillation (NPWTi-d) or branded instillation systems such as VAC Veraflo is considered promising but not established for routine use across all wound types. Systematic reviews and guideline bodies (for example NICE) note potential benefits for selected infected or nonhealing wounds but conclude there is insufficient high-quality evidence to support routine adoption and recommend further research.

Coding and Billing Guidance

Applicable CPT CodesCPT

97605	Negative pressure wound therapy (e.g., vacuum assisted drainage collection), utilizing durable medical equipment (DME), including topical application(s), wound assessment, and instruction(s) for ongoing care, per session; total wound(s) surface area less than or equal to 50 square centimeters.
97606	Negative pressure wound therapy (e.g., vacuum assisted drainage collection), utilizing durable medical equipment (DME), including topical application(s), wound assessment, and instruction(s) for ongoing care, per session; total wound(s) surface area greater than 50 square centimeters.
97607	Negative pressure wound therapy, (e.g., vacuum assisted drainage collection), utilizing disposable, non-durable medical equipment including provision of exudate management collection system, topical application(s), wound assessment, and instructions for ongoing care, per session; total wound(s) surface area less than or equal to 50 square centimeters.
97608	Negative pressure wound therapy, (e.g., vacuum assisted drainage collection), utilizing disposable, non-durable medical equipment including provision of exudate management collection system, topical application(s), wound assessment, and instructions for ongoing care, per session; total wound(s) surface area greater than 50 square centimeters.

Applicable HCPCS/DME CodesHCPCS

A6550	Wound care set, for negative pressure wound therapy electrical pump, includes all supplies and accessories.
A9272	Wound suction, disposable, includes dressing, all accessories and components, any type, each.
E2402	Negative pressure wound therapy electrical pump, stationary or portable.

Wound surface area (coding threshold)

Wound surface area thresholds≤ 50 sq cm versus > 50 sq cm determine CPT code selection (≤50 sq cm = 97605 or 97607; >50 sq cm = 97606 or 97608)

Durable vs disposable equipment97605 and 97606 describe NPWT utilizing durable medical equipment; 97607 and 97608 describe NPWT utilizing disposable, non‑durable equipment

Per‑session reportingEach CPT code describes NPWT per session and includes topical application(s), wound assessment, and instructions for ongoing care

Diabetic foot wound improvement threshold

Diabetic foot ulcer improvement threshold> 50% wound area reduction after a minimum of 4 weeks of standard wound therapy is required before adjunctive NPWT is recommended

Provider Requirements, Prior Authorization, and Documentation

Prior Authorization

Prior Authorization for NPWT and Associated Codes

Prior authorization may be required for outpatient NPWT services, DME (e.g., pumps, supplies), and disposable/single-use systems. When prior authorization is requested, documentation must demonstrate medical necessity and adherence to plan criteria, including that conservative therapy was tried or considered and contraindications are addressed.

Prior authorization applies to NPWT services and associated DME/supplies when submitted in the outpatient setting or at discharge from inpatient care.
Documentation must support a complete wound therapy program (see documentation callout) and indication-specific criteria before approval.

Prior Authorization

Prior authorization recommended for prophylactic/incisional NPWT

Prophylactic or incisional NPWT (closed surgical incisions) has mixed and evolving evidence. Prior authorization is recommended so that reviewers can assess patient-specific risk/benefit and review the clinical evidence provided with the request.

Insufficient or equivocal evidence for routine prophylactic/ciNPT use may lead to case-by-case review or requirement for additional documentation.

Clinical Background and Definitions

Negative pressure wound therapy applies subatmospheric pressure to wounds via a sealed dressing and suction pump to remove exudate, reduce edema, approximate wound edges, increase blood flow, and promote granulation tissue formation. It is intended as an adjunct for wounds that have not responded to conventional therapy.

Gustilo Grade III Fracture

DefinitionGustilo Grade III Fracture: an open fracture with extensive soft‑tissue damage or an open segmental fracture

Subclassification IIIAAdequate soft‑tissue coverage despite extensive laceration or high‑energy trauma regardless of wound size

Subclassification IIIBExtensive soft‑tissue loss with periosteal stripping and bone exposure; often requires soft‑tissue coverage (e.g., flap)

Subclassification IIICAssociated arterial injury requiring repair

Policy Summary

PayerUnitedHealthcare

PolicyNegative Pressure Wound Therapy (for Tennessee Only)

Policy CodePolicy CS157TN.J

Change TypeRevised contraindicationsevidence update

Effective DateJuly 1, 2025

Next Review DateN/A

Key ActionObtain and document a complete wound therapy program and evidence of failure after 30 days before seeking authorization for outpatient NPWT.

SourceLink

On This Page

Moreno RCT and Cochrane reviews provide mixed but sometimes favorable results.

Open fractures / traumatic wounds: Evidence is mixed: some meta-analyses and smaller trials report reduced infection with NPWT in open fractures, while large trials (e.g., WHIST) and systematic reviews show no clear difference for some long-term patient-reported outcomes; NPWT may be reasonable for temporary coverage or selected cases but is not uniformly superior to standard dressings.

Alves meta-analysis, WHIST trial, and Cochrane review highlight heterogeneity of findings.

Closed surgical incisions / prophylactic incisional NPWT (ciNPT): Evidence is mixed: some meta-analyses and Cochrane updates show reduced surgical site infections but heterogeneity, risk of bias, and potential for increased skin blistering; routine use is not uniformly supported—consider selective use for high-risk patients with supporting documentation.

Cochrane updates and recent meta-analyses show probable reduction in SSIs but uncertain effects on dehiscence and other outcomes.

Pilonidal disease: Insufficient evidence to support NPWT for pilonidal disease; RCT data do not show benefit in wound dehiscence, healing time, analgesic use, or return-to-activity outcomes.

Randomized data (Ensor et al.) do not support routine use.

NPWT with instillation (NPWTi-d): Systematic reviews and meta-analyses report higher primary closure rates and lower complication rates for NPWTi-d versus NPWT or standard care in heterogeneous wound populations, but overall evidence quality is limited and heterogeneity is high; further randomized trials are needed.

De Pellegrin, Gabriel, Kanapathy reviews show promising but low-certainty evidence.

Concurrent best practices: NPWT/NPWTi-d should be used in conjunction with good clinical practice such as debridement, appropriate antibiotics, optimization of vascular status, and offloading where relevant.

Document adherence to best practices alongside NPWT use.

Re-evaluation stepsBefore adjunctive NPWT, re-evaluate vascular status, infection control, and offloading to ensure optimization

Timing guidanceGuidelines suggest consideration of NPWT for chronic diabetic foot wounds that fail to demonstrate expected healing progression after 4 to 8 weeks

Recent systematic reviews and RCTs show variable results; provide surgical indication, patient risk factors, and outcomes data when requesting authorization.

Prior Authorization

Contraindications affect prior authorization

Presence of any contraindication to NPWT should be documented and will affect prior authorization decisions. The policy's contraindication list was recently revised and now includes anticoagulation therapy among conditions that may preclude coverage.

Contraindications include active bleeding or exposed vasculature, anticoagulation therapy, eschar or necrotic tissue, exposed bone/nerves/organs, malignancy in the wound, uncontrolled soft tissue infection or untreated osteomyelitis in the vicinity of the wound, and presence of an open fistula to organs or cavities.
If contraindications are present and unresolved, prior authorization may be denied.

Denial Risk

Contraindications may trigger denial

Use of NPWT may be declined if contraindications or unresolved clinical issues are present, or if documentation fails to establish medical necessity per the plan or contractual terms.

Denial triggers include active contraindications, lack of documentation that a complete wound therapy program was tried or considered, insufficient evidence for the requested indication (e.g., closed incisions or disposable systems), or failure to show progression criteria for adjunctive NPWT.
Denials will follow federal, state, or contractual plan terms where applicable.

Note

Reference governing plan terms

Benefit coverage decisions are governed by the member's federal, state, or contractual plan terms. In cases of conflict between this policy and a plan's contractual requirements, the plan terms prevail and may result in coverage denial even when medical criteria appear met.

Before relying on this policy for coverage decisions, reviewers must check the member's specific plan language and applicable legal requirements.
UnitedHealthcare reserves the right to modify policies; plan/contract terms and applicable laws govern coverage determinations.

Documentation Required

Required Clinical Documentation

Required clinical documentation must be submitted with prior authorization requests and claims. Incomplete documentation is a common basis for denial or delay.

Complete evaluation and wound measurements (surface area, depth) with dated serial measurements.
Documentation that a complete wound therapy program was tried or considered, including dressings to maintain moisture, debridement if present, nutritional assessment/intervention, and offloading or compression as applicable.
Provider statement of indication for NPWT and treatment goals; dates and results of prior therapies; and evidence of wound nonresponse to conventional care (e.g., no improvement after 30 days or ≥50% area reduction thresholds where guideline-specified).
Relevant imaging, microbiology, vascular assessments, and notes addressing infection status and wound bed preparation.

Documentation Required

Clinical justification and evidence documentation

Clinical justification must address the evidence base, patient-specific factors, and alternative therapies tried. Reviewers will consider the quality of evidence and applicability to the clinical scenario.

Provide clinical rationale linking the patient's wound type and characteristics to published guidelines and evidence (e.g., SVS, WHS, Cochrane reviews).
Note limitations of the evidence (risk of bias, heterogeneity) and explain why NPWT is appropriate for this patient despite any general uncertainties.
For disposable or instillation systems and prophylactic uses, include specific studies or guideline recommendations that support use in the presented clinical context.

Documentation Required

Required documentation for adjunctive NPWT

When NPWT is requested as an adjunctive therapy (e.g., after failure of standard care or prior to grafting), document wound progression, prior standard therapy duration, and objective improvement thresholds required by guidelines.

For diabetic foot ulcers: documentation of at least 4–8 weeks of standard or advanced dressings with failure to demonstrate expected healing (>50% reduction in area over specified interval) before initiating adjunctive NPWT per guideline recommendations.
For venous ulcers: documentation that compression therapy was used consistently for at least 30 days and was not efficacious before NPWT is considered.
For pressure ulcers: documentation of standard care measures (turning/positioning, support surface, moisture management) and lack of improvement before NPWT.

Step Therapy

Conservative Therapy Required Prior to NPWT / Step Therapy

Conservative therapy and stepwise care must be attempted or considered prior to NPWT initiation. NPWT is generally reserved for wounds that fail to respond to standard evidence-based care.

A complete wound therapy program (see documentation callout) must be tried or documented as not appropriate prior to NPWT.
For venous leg ulcers, NPWT is considered only after first-line compression therapy has failed.
Guidelines recommend standard wound care first and reserving NPWT for wounds that fail to improve (e.g., lack of ≥50% wound area reduction over the guideline-specified period).

NPIAP Pressure Injury Staging (Stage III/IV and Unstageable)

NPIAP Stage IIIFull‑thickness loss of skin with visible fat in the ulcer; granulation tissue and epibole often present; fascia/muscle/tendon/cartilage/bone not exposed; if slough or eschar obscures depth it is unstageable

NPIAP Stage IVFull‑thickness skin and tissue loss with exposed or directly palpable fascia, muscle, tendon, ligament, cartilage, or bone; epibole, undermining and/or tunneling often occur

Unstageable pressure injuryExtent of tissue damage cannot be confirmed because it is obscured by slough or eschar; removal of slough/eschar may reveal Stage III or IV

NPWTi‑d (definition)

DefinitionNegative‑pressure wound therapy with instillation and dwell time (NPWTi‑d): NPWT combined with periodic instillation of solutions into the wound followed by a dwell period before suction resumes

Intended benefitInstillation plus dwell aims to reduce bioburden, facilitate debridement, and improve primary wound closure rates compared with NPWT alone (evidence limited)

Evidence noteSystematic reviews report improved closure and lower complication rates but underscore limited quality and heterogeneity of studies

ciNPT / incisional NPWT (definition & evidence)

DefinitionClosed‑incision negative pressure therapy (ciNPT or incisional NPWT): application of negative pressure over a closed surgical incision, often used prophylactically to potentially reduce surgical site complications

Evidence summaryEvidence for routine use is mixed and limited by small or biased studies; selective use in high‑risk patients may be considered with documentation

Single‑use systems noteSome single‑use systems (e.g., PICO) have limited supporting evidence in specific populations such as post‑cesarean patients with obesity

NPWTi‑d (alternative reference/definition)

Alternative/confirmatory definitionNPWTi‑d describes NPWT combined with periodic instillation of wound solutions followed by a dwell period prior to resumption of negative pressure

Clinical contextUsed in orthoplastic and traumatic wounds in studies showing higher primary closure and lower complication rates versus NPWT or standard care, though evidence quality is limited

Research recommendationLarge randomized trials are needed to confirm benefits and define optimal use

PICO (single‑use NPWT for closed incisions)

PICO definition/referencePICO: a single‑use negative pressure wound dressing referenced by NICE as an option for closed surgical incisions in people at high risk of surgical site infection

NICE positionNICE concluded PICO dressings are associated with fewer SSIs and seromas compared with standard dressings but noted heterogeneity and variable study quality

Use implicationConsider as an option for high‑risk closed surgical incisions with documented rationale; routine use not supported without risk justification

Contraindications to NPWT (revised list)

Contraindication — anticoagulation therapyAnticoagulation therapy is listed as a contraindication to NPWT in the revised policy

Contraindication — uncontrolled infection/osteomyelitisUncontrolled soft tissue infection or untreated osteomyelitis within the vicinity of the wound is a contraindication

Other contraindicationsActive bleeding or exposed vasculature; eschar or necrotic tissue present; exposed bone, nerves, or organs; malignancy in the wound; presence of an open fistula to organs or cavities (as listed in policy exclusions/not medically necessary section)