Gastroenterology CPT® Codes for 2026 + Modifiers

Stay up-to-date with the latest 2026 gastroenterology CPT® codes and modifiers

Read Time: 2 minutes
Jan 12, 2026

Gastroenterology billing in 2026 reflects some of the most meaningful updates the specialty has seen in years. The AMA and GI Tri-Society (AGA, ACG, ASGE) have modernized anorectal testing, formalized bariatric endoscopy with a permanent CPT® code, expanded remote monitoring flexibility, and tightened compliance rules for screening colonoscopies.

Below is your updated guide to Gastroenterology CPT® codes and modifiers for 2026, including key revenue and compliance alerts your billing team needs to know.

GI denials usually aren’t “random”—they’re tied to predictable screening, documentation, and modifier mistakes.

We see the same friction points repeatedly in gastroenterology: screening vs. diagnostic mismatches on colonoscopy claims, incomplete documentation supporting medical necessity for anorectal testing, and inconsistent modifier use when multiple services occur in a single session. In 2026, those small gaps trigger big payer pushback.

Guarantee: We’ll identify the top denial causes in your GI claims and give you a clear plan to stop them.

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Evaluation and Management Codes Common in Gastroenterology

Many GI revenue-cycle issues start with E/M documentation—especially when an office visit turns into same-day testing, a procedure is scheduled based on symptoms, or a “screening” colonoscopy becomes diagnostic. If E/M is billed separately on the same date as another service, payers expect documentation that clearly supports a distinct, separately identifiable service (and appropriate modifier use when required).

CPT® Code	Description
99202–99205	New patient office/outpatient visits (levels 2–5)
99212–99215	Established patient office/outpatient visits (levels 2–5)
99221–99223	Initial hospital inpatient or observation care
99231–99233	Subsequent hospital inpatient or observation care

Document the “Why Today”

Tip: When an office visit and a procedure or test occur on the same date, clearly separate the assessment/plan (medical decision-making) from the procedure note to support modifier use and reduce “bundled” denials.

Getting paid for GI E/M is hard when payers think it’s “bundled” into the procedure.

We see denials when 99213–99215 (or 99202–99205) are billed on the same day as testing or a procedure and the note doesn’t clearly justify a separate, significant service—especially when modifier -25 is used. We know what payers look for and where GI documentation typically fails.

Guarantee: We’ll pinpoint exactly why your E/M claims are denied and show you what to change so the next batch pays.

Analyze My E/M + Procedure Denials

Contact us to get a Denial Snapshot highlighting E/M + procedure denial drivers and the fixes that restore reimbursement.

Major 2026 CPT® Code Additions & Overhauls

Gastroenterology saw several “structure-level” changes in 2026 that affect coding, documentation expectations, and how claims are reviewed. The most common issues we see happen when teams keep older workflow assumptions (like legacy anorectal testing reporting or older HCPCS crosswalks) even after codes and descriptors have changed.

Endobariatrics: Endoscopic Sleeve Gastroplasty (ESG)

CPT® Code	Description	2026 Impact
43889	Gastric restrictive procedure, transoral, endoscopic sleeve gastroplasty (ESG)	Replaces HCPCS C9784; includes APC when performed

Global Period: 43889 carries a 90-day global period. All routine follow-up care is bundled into the surgical payment. Practices must ensure post-op visits are not separately billed unless unrelated.

Practical billing note: When claims deny, it’s often not the code—it’s the supporting documentation and how the episode is framed. Align your op note elements (indication, technique, device/suture method as applicable, findings, and complications) with payer expectations so the claim is defensible on first pass.

Anorectal Physiology Testing Modernization

The legacy codes 91120 and 91122 have been deleted. They are replaced with more comprehensive and bundled testing descriptors.

CPT® Code	Description
91124	Rectal sensation, tone, and compliance testing (e.g., barostat)
91125	Anorectal manometry including anal sphincter pressures, reflexes, rectal sensation, and balloon expulsion (when performed)

These updated codes better reflect comprehensive pelvic floor disorder testing and reduce the need for multiple line-item reporting.

Common denial trigger: When payers don’t see a clear medical-necessity story (symptoms, failed conservative management when applicable, and test intent tied to clinical decision-making), they’re more likely to deny—even if the code is correct. Make sure the note answers “what are we evaluating, and what will we do with the result?”

Liver Tumor Ablation “Graduation”

CPT® Code	Description	Update
47384	Percutaneous irreversible electroporation (IRE) of liver tumor(s)	Graduated from Category III (0600T) to permanent Category I

This permanent Category I status significantly improves reimbursement stability. Imaging guidance is included.

When GI codes “change,” payers don’t just update software—they tighten edits and documentation expectations.

We see preventable denials when teams don’t fully operationalize 2026 changes—like treating anorectal testing as legacy line-item reporting or mishandling newer bariatric endoscopy episodes. The result is delayed cash flow, repeated requests for records, and rework that eats staff time.

Guarantee: We’ll identify the exact code-transition and documentation risks in your GI workflow and show you how to fix them.

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Remote Monitoring for Chronic GI Conditions

For patients with IBD, cirrhosis, obesity, or chronic liver disease, remote monitoring continues to expand in 2026. The opportunity is real—but so is payer scrutiny. Claims typically pay when you can demonstrate the required device/supply elements, an automatic transmission workflow (when required), and clear documentation of time spent reviewing data and managing treatment.

Code	Description
99445	Remote monitoring supply and transmission (2–15 days)
99454	Remote monitoring supply (16+ days; automatic transmission required)
99470	Remote monitoring treatment management, first 10 minutes

Lower Management Threshold: 99470 lowers the prior 20-minute threshold, allowing reimbursement for the first 10 minutes of data review.

Compliance Update: For 2026, 99454 requires automatic device transmission. Manual patient logs, emailed food diaries, or text-reported symptom trackers no longer qualify.

Operational reminder: Remote monitoring revenue often fails due to workflow, not coding. If the clinical team collects data but the billing team can’t prove transmission requirements or time thresholds, payers treat the claim as non-compliant—even when the patient benefited clinically.

Remote monitoring in GI is a payer “favorite” to deny when the workflow isn’t airtight.

We commonly see denials tied to missing documentation of device transmission requirements, unclear time tracking, or notes that don’t connect data review to treatment decisions. In 2026, the automatic transmission requirement for 99454 is an easy way for payers to reject claims.

Guarantee: We’ll identify the top compliance gaps in your remote monitoring claims and provide fixes that reduce denials.

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Contact us to receive a Denial Snapshot that pinpoints why your remote monitoring claims aren’t getting paid—and how to fix it.

Core Gastroenterology Procedure Codes

Foundational endoscopy services remain unchanged structurally but are subject to a -2.5% efficiency adjustment to work RVUs in 2026. That makes clean claims more important—because when reimbursement tightens, denials and delays hurt more.

Upper GI Endoscopy (EGD)

CPT® Code	Description
43235	Diagnostic EGD
43239	EGD with biopsy
43249	EGD with balloon dilation (<30 mm)

Colonoscopy

CPT® Code	Description
45378	Diagnostic or screening colonoscopy
45380	Colonoscopy with biopsy
45385	Colonoscopy with snare polypectomy
45384	Colonoscopy with hot biopsy forceps

Screening Conversion Alert: If a colonoscopy begins as screening (Z12.11) but a polyp is removed, Medicare requires Modifier -PT. Commercial payers may require Modifier -33 for preventive designation.

Documentation tip: Make sure the procedure documentation supports the “why” and the “what changed.” Screening-to-diagnostic claims are frequently denied when the diagnosis, modifier, and documentation don’t match the clinical story.

Colonoscopy denials often come down to screening logic, modifier selection, and diagnosis support—not the procedure itself.

We see payers deny or reprocess claims when screening intent isn’t clearly supported, when -PT or -33 is missing/misapplied, or when diagnosis selection doesn’t align with the claim narrative. In 2026, payers are using more automated edits to flag inconsistencies.

Guarantee: We’ll identify exactly why your endoscopy claims aren’t paying and give you a fix plan you can implement immediately.

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Gastroenterology Diagnostic Testing CPT® Codes To Know

Diagnostic testing is a frequent denial trigger in GI—especially when medical necessity, symptom severity, and prior conservative management are not clearly documented. Even when payers approve the test, they may deny the claim if the note doesn’t support why the test was appropriate on that date.

CPT® Code	Description
91124	Rectal sensation, tone, and compliance testing (e.g., barostat)
91125	Anorectal manometry including anal sphincter pressures, reflexes, rectal sensation, and balloon expulsion (when performed)

Medical-necessity reminder: Clearly document symptoms (duration, severity, functional impact), prior therapies, and how results will impact the plan of care. This is the “defense” payers look for when deciding whether to reimburse.

Diagnostic testing denials happen when payers don’t see medical necessity—so they don’t pay.

For services like anorectal physiology testing, we commonly see denials tied to missing indications, incomplete symptom documentation, or lack of conservative management detail in the note. We know the patterns payers use to deny these tests and what documentation makes claims defensible.

Guarantee: We’ll identify the top medical-necessity denial triggers in your GI testing claims and show you how to correct them.

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Common Surgical Procedures and 2026 New Standards

GI teams are also navigating shifting reimbursement and payer edits for higher-acuity services. The 2026 environment rewards tight documentation—because the more expensive the claim, the more likely it is to be reviewed. Make sure your operative/procedure documentation is consistent, complete, and clearly supports medical necessity and technique.

CPT® Code	Description	2026 Focus
43889	Gastric restrictive procedure, transoral, endoscopic sleeve gastroplasty (ESG)	90-day global; ensure post-op billing compliance
47384	Percutaneous irreversible electroporation (IRE) of liver tumor(s)	Now Category I; imaging guidance included

High-dollar GI claims hurt the most when they deny—because every day unpaid is real revenue at risk.

We see denials and payer requests spike when documentation doesn’t clearly support newer or higher-acuity services. Even when the CPT® code is correct, incomplete medical-necessity support or missing operative detail can stall reimbursement.

Guarantee: We’ll uncover what’s blocking reimbursement on your high-dollar claims and give you a step-by-step fix plan.

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A Quick 2026 “Watch List” for GI Teams

The highest-risk denials and delays in 2026 tend to come from workflow “misses,” not complex coding theory. Here are the items most likely to trigger rejections, recoupments, or repeated requests for records if they aren’t built into daily processes.

Screening vs. diagnostic consistency: Ensure diagnosis, intent, and modifiers align for colonoscopies that convert to diagnostic work.
Anorectal testing modernization: Retire deleted codes (91120/91122) and align documentation to the newer bundled descriptors.
Remote monitoring compliance: Confirm automatic transmission requirements for 99454 are met and documented.
Global period awareness: Treat 90-day global rules for 43889 as an operational compliance item, not an afterthought.

If your team misses just one 2026 compliance detail, payers will reject the claim—and you’ll be stuck reworking it.

We routinely see practices lose time and cash flow due to preventable rejections and reprocessing—especially around screening conversions, remote monitoring requirements, and documentation that doesn’t match updated code descriptors.

Guarantee: We’ll identify the exact 2026 risk points in your GI billing workflow and show you how to eliminate them.

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Essential Gastroenterology Modifiers for 2026

Modifier	Description	2026 Application
-33	Preventive Service	Used with screening colonoscopy to indicate zero cost-sharing
-PT	Screening converted to diagnostic	Required by Medicare when biopsy/polypectomy occurs
-25	Separate E/M	For unrelated same-day visits (e.g., IBD flare)
-53	Discontinued Procedure	Use when colonoscopy is incomplete due to prep or safety
-XS	Separate Structure	Preferred over -59 in 2026 for distinct lesions

CMS continues encouraging use of X-modifiers (like -XS) instead of the general -59 to reduce audit risk.

Modifiers are where GI claims go to die—especially preventive and screening conversion rules.

We see payers deny claims when -PT or -33 is missing/misapplied, when -25 is appended without a clearly separable E/M “story,” or when distinct-service logic isn’t defensible. We know which modifier mistakes repeatedly block payment—and how to correct them.

Guarantee: We’ll identify your top modifier-driven denials and tell you exactly what to change to prevent repeat denials.

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Common ICD-10-CM Codes Used in Gastroenterology

ICD-10 Code	Description
Z12.11	Encounter for screening for malignant neoplasm of colon
K50.90	Crohn’s disease, unspecified, without complications
K51.90	Ulcerative colitis, unspecified, without complications
K21.9	Gastro-esophageal reflux disease without esophagitis
K74.60	Unspecified cirrhosis of liver
R10.13	Epigastric pain
K92.1	Melena

A “right CPT®” can still deny if the diagnosis doesn’t support medical necessity.

We see denials when ICD-10 selection doesn’t align with payer policy—especially around screening colonoscopies (Z12.11), IBD care (K50.90/K51.90), cirrhosis management (K74.60), and symptom-driven visits that were scheduled as “screening.” Medical-necessity mismatches are a silent AR killer because they look “coded” but won’t pay.

Guarantee: We’ll identify your most common CPT®/ICD mismatches and provide fixes that reduce medical-necessity denials.

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2026 Revenue & Compliance Warnings

Facility vs. Office Gap

The 2026 fee schedule significantly increased payment for office-based endoscopy while reducing facility-based reimbursement in ASCs and hospitals. Practices capable of performing small-bore dilations or hemorrhoid bandings in-office may see improved margins.

E/M Add-On Code G2211

Gastroenterologists managing complex, longitudinal conditions such as IBD, Hepatitis C, or cirrhosis can report add-on code G2211 with outpatient E/M visits. This provides incremental revenue for ongoing specialty care.

Screening vs. Diagnostic Scrutiny

Payers are using AI-based claim review systems in 2026 to detect inconsistencies between diagnosis and intent. If a patient presents with symptoms but is scheduled as screening, the claim must reflect diagnostic coding to avoid audit flags.

GI compliance risk usually shows up as denials first—then audits later.

When screening logic, diagnosis support, and documentation structure don’t match payer policy, claims don’t just deny—they can trigger repeated requests for records or retrospective scrutiny. We help teams close those gaps before they become expensive problems.

Guarantee: We’ll identify the compliance-driven denial patterns in your GI claims and give you a clear fix plan.

Reduce My GI Compliance Denials

Contact us to receive a Denial Snapshot that highlights compliance risks and the documentation fixes that protect reimbursement.

2026 Gastroenterology Summary Table

2026 Status	Code(s)	Impact on GI Practice
New Category I	43889	Permanent ESG code with 90-day global period
Modernized	91124–91125	Replaces legacy anorectal physiology codes
Graduated	47384	IRE liver ablation now permanent Category I
Remote Monitoring	99445, 99470	Lower threshold for chronic GI data review
Efficiency Adjustment	45378–45385	-2.5% work RVU reduction

Gastroenterology Billing Tips for 2026

Make screening logic airtight. Align diagnosis, intent, and modifiers for colonoscopy claims that convert to diagnostic.
Retire legacy anorectal testing codes. Update templates and charge capture to 91124–91125 and document medical necessity clearly.
Build remote monitoring compliance into workflow. Confirm 99454 automatic transmission requirements and track time consistently for 99470.
Respect global periods. Ensure routine post-op care for 43889 is not billed separately unless unrelated.
Protect E/M reimbursement. When billing E/M with other services, separate the clinical “story” from the procedure note and apply modifiers appropriately.

If these “simple tips” aren’t built into your workflow, denials keep coming back—month after month.

Most teams know the rules, but denials persist because templates, charge capture, and documentation habits don’t match what payers require for 2026—especially around screening conversions, anorectal testing modernization, and remote monitoring compliance.

Guarantee: We’ll deliver a Denial Snapshot that identifies the exact process gaps causing denials—and a plan to fix them.

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Contact us to receive a Denial Snapshot that turns your denial patterns into a clear action plan for higher reimbursement.

Final Thoughts

Gastroenterology billing in 2026 centers on modernization. ESG is now permanent. Anorectal physiology testing is streamlined. Remote monitoring is easier to bill but more tightly regulated. At the same time, reimbursement pressure makes clean documentation and correct modifier use essential.

Work with an expert medical billing team

If you’re still chasing GI denials, you’re losing revenue and time you’ll never get back.

Whether your pain is screening conversion rules (-PT, -33), modifier issues, diagnosis support, remote monitoring compliance, or documentation structure, we’ve seen these exact problems across gastroenterology and know how to correct them quickly.

Guarantee: We’ll identify your top denial causes and give you a concrete plan to fix them—so you can get paid.