Obtain prior authorization for implants, revisions, removals, and related billing codes

Prior authorization is required for implantation, revision, removal, and related CPT/HCPCS codes when selection criteria in the policy are being used to determine medical necessity.

• Applies to listed CPT codes for implantation, revision, removal, and pulse generator programming/analysis (see coding section).

Prior authorization must document indication for GES/IGS (humanitarian/exempt uses only)

Authorization for implantation of investigational or humanitarian-exemption gastric stimulation devices should include documentation of the indication (for Enterra: diabetic or idiopathic gastroparesis) and prior failed conservative therapy.

• Enterra is approved as a humanitarian exemption device only for diabetic and idiopathic gastroparesis; obesity indications lack consistent benefit.

Document refractory gastroparesis and objective delayed gastric emptying for prior authorization

Prior authorization requests should document refractory gastroparesis with objective delayed gastric emptying on GES and prior failure of conservative therapies including dietary modification and antiemetics/prokinetics.

• G-POEM medically necessary criteria require GES showing >60% retention at 2 hours and/or >10% at 4 hours, symptom duration >6 months, and inadequate response to conservative treatment including a trial of at least one prokinetic.

Document expert‑center selection and prior therapies for advanced procedures

Prior authorization should show that patients selected for procedures such as G-POEM are carefully chosen and that the procedure will be performed at tertiary/expert centers after failure of prior treatments.

• Society guidance recommends G-POEM be performed in expert centers only, preferably in the context of clinical trials.

Submit symptom severity, prior therapies, diverticulum details, and center expertise for POEM variant authorization

For POEM variants, prior authorization should include symptomatic severity, prior therapies tried, diverticulum characteristics (type/size), and evidence of provider/center experience.

• Documentation should include validated symptom scores (e.g., Eckardt) and details on prior conservative or endoscopic/surgical interventions.

Provide documentation of temporary GES predictive testing when used to justify permanent GES

If a center uses temporary stimulating electrodes (tGES) to select responders, prior authorization may require submission of documentation of that predictive testing and its results to justify permanent implantation.

• Describe the tGES method used (endoscopic or percutaneous leads), symptom monitoring during stimulation, and interpretation of response.

Confirm plan coverage and prior authorization requirements with the payer

Verify plan-specific coverage and prior authorization requirements with the member's plan because Clinical Policy Bulletins do not guarantee coverage and plan provisions govern.

• Providers are responsible for confirming benefits and prior authorization rules with the payer before proceeding.

Document failure of conservative therapy including dietary changes and ≥1 prokinetic before G-POEM

Prior to G-POEM, members must have failed conservative treatments including dietary modification and a trial of at least one prokinetic agent.

• Acceptable prokinetics listed include domperidone, metoclopramide, or erythromycin per the policy's G-POEM criteria.

Ensure conservative/prokinetic/antiemetic therapy has failed before invasive interventions

Candidates for invasive interventions (GES or G-POEM) should have refractory symptoms after conservative/prokinetic/antiemetic therapy; prior authorization should reflect this treatment history.

• Many series included patients who had failed Botox, transpyloric stent, PEGJ, or medical therapy prior to advanced procedures.

Position G-POEM after conservative and prior endoscopic/surgical interventions in treatment sequencing

G-POEM is an organ‑sparing option considered after failure of conservative measures and may be considered relative to prior interventions such as endoscopic dilation, Botox, stenting, or surgical pyloroplasty.

• Document prior interventions and rationale for choosing G-POEM as the next step in therapy.

Consider prior pyloric-targeted therapies (Botox, prior GES) when evaluating candidates

When evaluating candidates, consider prior pyloric‑targeted therapies (e.g., Botox, prior gastric stimulator) because published series often report these prior treatments and they may predict response to G-POEM.

• Meta-regression identified prior treatment with Botox and gastric stimulator as potential predictors of clinical success with G-POEM.

Sequence therapy: consider established septotomy/surgical options before advanced tunneling techniques

Consider less invasive established endoscopic septotomy or surgical options when appropriate before advanced tunneling techniques like Z-POEM or D-POEM; document reasons if proceeding directly to advanced techniques.

• Authors note randomized and comparative studies are lacking; procedure choice should be individualized and justified.

If tGES used as a selection step, submit detailed tGES method and response documentation

Temporary GES (via G‑tube or endoscopic mucosal leads) has been used by some centers as a selection step to identify likely responders before permanent implantation; documentation of tGES procedure and response should be submitted if relied on for decision-making.

• tGES techniques vary (trans-nasal leads, G-tube electrodes, laparoscopic temporary electrodes) and some are not commercially available; document method and limitations.

Include GES confirmation, prior conservative management, and prokinetic trials in documentation

Documentation must demonstrate diagnosis confirmation by gastric emptying study when required, prior conservative management and trials of prokinetic agents, and reason for revision/replacement if applicable.

• For G-POEM, include GES results meeting policy thresholds (>60% at 2 hours and/or >10% at 4 hours), symptom duration, and trial of at least one prokinetic.

Submit pre-operative evaluation (upper endoscopy, GES; pH/manometry if indicated) for G-POEM/POP

Pre-operative work‑up for G-POEM/POP in reported series included upper endoscopy and gastric emptying study; pH study and esophageal manometry were performed when concomitant fundoplication was considered.

• Ensure pre-op testing and rationale for additional studies are documented in the prior authorization record.

Provide baseline GCSI and GES results as part of clinical assessment documentation

Baseline assessments reported in studies include the Gastroparesis Cardinal Symptom Index (GCSI) and gastric emptying scintigraphy (GES); include these measures in authorization and follow-up documentation.

• Some authors proposed selection thresholds using GCSI and GES; include baseline scores and objective test results.

Document baseline and follow‑up GCSI and 4‑hour GES results to show response

Documentation should include baseline and follow‑up GCSI scores and gastric emptying scintigraphy results (4‑hour retention) to demonstrate clinical response as used in cited studies.

• Studies used GCSI change and 4‑hour GES retention to define treatment success; include these data in outcomes reporting.

Provide indication, prior treatments, diverticulum characteristics, and center experience for POEM variants

For POEM variants treating diverticula, include indication (symptomatic diverticulum with dysphagia/regurgitation/aspiration), prior conservative or alternative therapies, diverticulum type and size, and provider/center experience.

• Include validated symptom scores (e.g., Eckardt, Kothari‑Haber) and documentation of prior treatments or rationale for advanced endoscopic approach.

Submit baseline/post‑tGES EGG measures, GETs, and standardized symptom scores when using tGES

When tGES is used, documentation should include baseline and post‑tGES electrogastrogram (EGG) measures (frequency, amplitude, propagation), gastric emptying tests, and standardized patient‑reported outcome scores to support interpretation.

• EGG measures correlated with symptoms and GET results in studies and may help identify patients likely to require GES.

Providers must verify member coverage and prior authorization rules with the plan

Verify benefits and prior authorization requirements with the member's plan; Clinical Policy Bulletins are a partial description of plan benefits and do not constitute a guarantee of coverage.

• Providers are responsible for confirming plan‑specific provisions before scheduling procedures.

Denial risk: investigational procedures may be denied without evidence meeting policy criteria

Procedures considered experimental/investigational—such as G-POEM for indications other than the policy-specified severe gastroparesis criteria, temporary GES to predict permanent GES success, or use of a second gastric electrical stimulator—may be denied as not established.

• Temporary GES for prediction of success is explicitly listed as experimental and investigational in the policy.

Denial risk: humanitarian‑exemption device use outside approved indications may not be covered

Devices approved under a humanitarian exemption (Enterra) are limited to diabetic and idiopathic gastroparesis; use outside these indications may be denied.

• UpToDate and policy state Enterra is approved only for diabetic and idiopathic gastroparesis.

Potential denial trigger: lack of documentation meeting proposed GCSI and GES thresholds (GCSI ≥2.0; retention >20%)

One study proposed selection thresholds of GCSI ≥ 2.0 and gastric retention >20%; absence of documentation showing patients meet such proposed criteria may prompt questions or denial.

• This proposed threshold came from a relatively small retrospective study and is not the policy's primary G-POEM threshold.

Denial risk: procedures performed outside expert centers or trial contexts may be restricted

Guidelines recommend G-POEM be considered only in carefully selected patients and performed in expert centers, preferably in clinical trials; lack of expert‑center performance or trial context may increase denial risk.

• ESGE and AGA/ACG guidance emphasize performance in tertiary centers with multidisciplinary expertise.

Denial risk: limited evidence or lack of center expertise for newer POEM variants may lead to denial

Procedures lacking randomized trial evidence, long‑term outcomes, or performed outside centers with appropriate expertise (e.g., D‑POEM, Z‑POEM) carry higher risk for coverage denial when medical necessity is not clearly documented.

• Policy notes limited randomized data and variable long‑term outcomes as reasons for restricting routine coverage.

Denial risk: inadequate tGES technique or documentation (electrode dislodgement, insufficient wash‑out) may invalidate results

tGES testing has validity risks—studies reported high electrode dislodgement rates and small sample sizes; inadequate technique, dislodgement, insufficient wash‑out, or incomplete documentation may lead to questioning of test validity and denial.

• One trial reported electrode dislodgement in 22% of patients and cited potential carry‑over effects due to insufficient wash‑out.

Coverage contingent on plan benefits—verify contract terms before proceeding

Coverage is contingent on the member's plan benefits and contract language; Clinical Policy Bulletins do not guarantee coverage and administrative or contractual limitations may apply.

• Confirm plan terms and prior authorization requirements before scheduling treatment.