45378

🧬 CPT 45378 - Colonoscopy, Flexible; Diagnostic

Quick Reference

wRVU: ~3.16 · Global: 000 · Assistant: ❌ Not Payable · Bilateral: ❌ N/A · Type: Diagnostic — Separate Procedure

---

📋 Full Code Descriptor

☑️ CPT 45378 - Colonoscopy, flexible; diagnostic, including collection of specimen(s) by brushing or washing, when performed (separate procedure)

CPT 45378 is the base/parent code for the entire family of flexible colonoscopy procedures. It describes a diagnostic examination of the entire colon, from the rectum to the cecum, and may include examination of the terminal ileum.

The descriptor’s parenthetical “including collection of specimen(s) by brushing or washing, when performed” means those specific specimen collection methods (e.g., cytology brushings) are bundled and not separately reportable. However, if a biopsy is taken using forceps, the code upgrades to 45380.

The designation “(separate procedure)” indicates that 45378 represents a distinct procedural service that may be subject to bundling when performed alongside other procedures in the same anatomic area.

This is one of the highest-volume procedures in medical coding, utilized heavily for both diagnostic symptom workups and preventive colorectal cancer screenings.

---

🔭 Procedure Overview

What the Endoscopist Does

1. Patient is placed in the left lateral decubitus position and sedated (moderate sedation or MAC/general anesthesia).
2. A digital rectal examination (DRE) is typically performed prior to scope insertion.
3. A flexible video colonoscope is introduced transanally.
4. Structures systematically examined as the scope is advanced:
   • Anal canal and rectum
   • Sigmoid colon
   • Descending colon
   • Splenic flexure
   • Transverse colon
   • Hepatic flexure
   • Ascending colon
   • Cecum (identifying the appendiceal orifice and ileocecal valve)
   • Terminal ileum (when indicated)
5. The endoscopist carefully inspects the mucosa during both insertion and standard slow withdrawal.
6. Brushings or lavage specimens are collected if indicated (bundled).
7. Photo documentation of the anatomical landmarks (especially the cecum) is captured to prove completion.

Scope Reach Defined

To be billed as a completed colonoscopy (45378), the endoscope must reach the cecum.

Structure	Included in 45378
Rectum & Sigmoid	✅ Always
Descending & Transverse	✅ Always
Ascending Colon	✅ Always
Cecum	✅ Always (Must be reached for a complete code)
Terminal Ileum	✅ When appropriate
Failure to reach cecum	❌ — Requires modifier -52 or -53

---

💰 Valuation & Reimbursement

Field	Value
wRVU	~3.16 (Subject to annual MPFS updates)
Global Period	000 days
Pre-op Period	0 days
Post-op Period	0 days
Assistant Surgeon Payable	❌ No
Bilateral Procedure	❌ Not applicable
Co-Surgeon (-62)	❌ Not applicable
Facility vs. Non-Facility RVU	Facility RVU lower (ASC/hospital); Non-facility (office) higher
Anesthesia	Separately reportable; moderate sedation is NOT bundled. Endoscopist bills 99152, 99153 if personally administered. Anesthesia provider bills 00811 or 00812.

---

🌲 Code Tree / Code Family

CPT 45378 anchors the Colonoscopy code family (45378-45398). All codes in this family include the diagnostic examination. The add-on or upgraded codes are selected based on the most complex service performed.

Only Report One Primary Colonoscopy Code Per Session

When multiple interventions are performed during a single session, report the most complex procedure as the primary code.

45378 ── Diagnostic Colonoscopy (base); brushing/washing bundled ← THIS CODE
│
├── 45379 ── + Removal of foreign body(s)
├── 45380 ── + Biopsy, single or multiple
├── 45381 ── + Directed submucosal injection(s), any substance
├── 45382 ── + Control of bleeding, any method
├── 45384 ── + Removal of tumor(s)/polyp(s) by hot biopsy forceps
├── 45385 ── + Removal of tumor(s)/polyp(s) by snare technique
├── 45386 ── + Dilation by balloon
├── 45388 ── + Ablation of tumor(s), polyp(s), or other lesion(s)
├── 45389 ── + Placement of stent
├── 45390 ── + Endoscopic mucosal resection (EMR)
├-─ 45391 ── + Endoscopic ultrasound (EUS)
├── 45393 ── + Decompression (for pathologic distention)
└── 45398 ── + Band ligation(s) (e.g., hemorrhoids)

---

✅ Includes (Bundled Into 45378)

The following services are inherent to the procedure and not separately reportable:

• Introduction and advancement of the endoscope to the cecum
• Visual inspection of the entire colon
• Photodocumentation (images/video capture)
• Specimen collection by brushing or washing/lavage
• Digital Rectal Exam (DRE) performed prior to scope insertion
• Standard scope withdrawal and mucosal re-examination
• Pre- and post-procedure assessment and monitoring

---

❌ Excludes / Separately Reportable

Do NOT bundle

— report separately when documented and medically necessary

Code	Descriptor	Notes
45380	Colonoscopy with biopsy	Upgrades 45378 — use when forceps biopsy is taken; do NOT report both
45385	Colonoscopy with snare polypectomy	Upgrades 45378
45382	Colonoscopy with control of bleeding	Upgrades 45378
99152-99153	Moderate sedation services (by same physician)	Separately reportable when endoscopist administers sedation
00811 / 00812	Anesthesia for lower GI procedures	Reported by anesthesia provider (00812 for screening, 00811 for diagnostic)
88305	Surgical pathology, gross and microscopic	Reported by the pathology department for interpreting collected tissue

---

🏥 MS-DRG Mapping

Inpatient Context

Like EGDs, 45378 is predominantly an outpatient/ASC procedure. When performed on an inpatient basis, MS-DRG assignment is driven by the principal diagnosis (e.g., lower GI hemorrhage, colitis) rather than the procedure code itself.

Common Inpatient DRG Contexts for 45378

MS-DRG	Title	Common Principal Dx
377	GI Hemorrhage with MCC	K62.5, K57.31, K92.2
378	GI Hemorrhage with CC	K62.5, K57.31
379	GI Hemorrhage without CC/MCC	K62.5, K92.1
385	Inflammatory Bowel Disease with MCC	K50.90, K51.90
386	Inflammatory Bowel Disease with CC	K50.90, K51.90
387	Inflammatory Bowel Disease without CC/MCC	K51.90

---

🔬 Commonly Associated ICD-10-CM Diagnoses

Screening & Surveillance Indications

ICD-10-CM	Descriptor	HCC	Notes
Z12.11	Encounter for screening for malignant neoplasm of colon	Non-HCC	Primary code for routine screening colonoscopy
Z86.010	Personal history of colonic polyps	Non-HCC	Surveillance colonoscopy indication
Z80.0	Family history of malignant neoplasm of digestive organs	Non-HCC	High-risk screening indication
Z85.038	Personal history of other malignant neoplasm of large intestine	Non-HCC	History of colon cancer

Diagnostic Indications

ICD-10-CM	Descriptor	HCC	Notes
K62.5	Hemorrhage of anus and rectum	Non-HCC	Lower GI bleed (hematochezia)
K92.1	Melena	Non-HCC	Dark, tarry stools
K57.30	Diverticulosis of large intestine without bleeding	Non-HCC	Common finding
K57.31	Diverticulosis of large intestine with bleeding	Non-HCC	Common source of lower GI hemorrhage
R19.4	Change in bowel habit	Non-HCC	Symptom-driven diagnostic scope
R19.7	Diarrhea, unspecified	Non-HCC	Chronic diarrhea workup
D50.0	Iron deficiency anemia secondary to blood loss	Non-HCC	Occult GI blood loss workup
K50.90	Crohn’s disease, unspecified, without complications	Non-HCC	Inflammatory Bowel Disease (IBD)
K51.90	Ulcerative colitis, unspecified, without complications	Non-HCC	Inflammatory Bowel Disease (IBD)
K63.5	Polyp of colon	Non-HCC	Finding code (if removed, code upgrades from 45378)
C18.9	Malignant neoplasm of colon, unspecified	HCC 10 (v24) / HCC 17 (v28)	Malignancy found during diagnostic/screening exam

---

🔧 Applicable Modifiers

Screening Modifiers

The application of modifiers for screening colonoscopies is strictly enforced to ensure patients receive correct preventive care benefits (waived copays/deductibles) under the Affordable Care Act and Medicare rules.

Modifier	Name	When to Use with 45378
-33	Preventive Services	Used for commercial payers to indicate the procedure was a preventive screening (even if it turns diagnostic).
-PT	CRC Screening Converted to Diagnostic	Medicare specific: Used when a screening colonoscopy turns into a diagnostic/therapeutic one (e.g., polyp found). Added to the diagnostic code (e.g., 45385--PT).
-52	Reduced Services	Procedure was planned but the endoscope did not reach the splenic flexure (e.g., poor prep, obstructing tumor) in a non-Medicare patient.
-53	Discontinued Procedure	Medicare specific for incomplete colos: Used when the scope is advanced past the splenic flexure but fails to reach the cecum.
-59	Distinct Procedural Service	When 45378 is performed at a separate session on the same date as another GI procedure (like an EGD).
-73	Discontinued Outpatient Hospital Procedure Prior to Anesthesia	Facility use; procedure discontinued before anesthesia.
-74	Discontinued Outpatient Hospital Procedure After Anesthesia	Facility use; procedure discontinued after anesthesia administered.

---

📖 Documentation Requirements

For compliant reporting and audit defense, the endoscopy report must explicitly document:

1. Indication — Screening (average vs. high risk) or Diagnostic (specific symptoms like R19.4, K62.5).
2. Prep Quality — Excellent, good, fair, or poor (crucial if incomplete).
3. Extent of Examination — Explicit documentation that the cecum was reached and visualized (e.g., “appendiceal orifice and ileocecal valve were identified”).
4. Withdrawal Time — Often recorded for quality metrics (benchmark is >6 minutes).
5. Findings — Detail all polyps, diverticula, erythema, or normal mucosa.
6. Interventions — If NO interventions/biopsies were performed, explicitly state this to support 45378.
7. Photodocumentation — Confirmation that cecal landmarks were photographed.

---

🧪 Coding Examples

Example 1 — Normal Screening Colonoscopy (Medicare)

A 65-year-old asymptomatic Medicare patient presents for a routine 10-year screening colonoscopy. The scope is advanced to the cecum. Prep is excellent. Mucosa is entirely normal throughout the colon. Scope is withdrawn.

CPT: 45378 ICD-10-CM: Z12.11 — Encounter for screening for malignant neoplasm of colon HCPCS Alternative: Note that for Medicare, HCPCS code G0121 (Screening colonoscopy, not high risk) is often required instead of 45378 for a purely normal screening.

---

Example 2 — Commercial Patient Screening, Polyp Found and Removed

A 50-year-old patient with commercial insurance presents for a screening colonoscopy. The scope is advanced to the cecum. A 10mm polyp is found in the descending colon and is removed via cold snare.

CPT: 45385--33 (Code upgrades to snare polypectomy; Modifier -33 indicates it started as a screening) ICD-10-CM: - Z12.11 — Encounter for screening (Primary)

• D12.4 — Benign neoplasm of descending colon (Secondary)

---

Example 3 — Diagnostic Incomplete Colonoscopy

A 70-year-old male presents with hematochezia (K62.5). The colonoscope is advanced. However, due to an exceptionally tortuous colon and severe diverticulosis, the endoscopist cannot safely advance the scope past the splenic flexure. The procedure is aborted to prevent perforation.

CPT: 45378--53 (Modifier -53 for discontinued procedure before reaching cecum) ICD-10-CM:

• K62.5 — Hemorrhage of anus and rectum
• K57.30 — Diverticulosis of large intestine without bleeding

---

⚠️ Coding Pitfalls & Compliance Notes

Common Errors

• Reporting 45378 when a biopsy or polypectomy was performed: If any tissue is removed, the code must be upgraded (e.g., 45380, 45384, 45385). You cannot bill 45378 alongside an interventional colonoscopy code for the same session.
• Failing to append incomplete modifiers: If the operative report explicitly states the cecum was not reached, billing a clean 45378 is fraudulent. You must append -52 or -53 depending on payer rules and how far the scope advanced.
• Incorrect Screening vs. Diagnostic diagnosis sequencing: If a patient comes in for a screening and a polyp is found, the screening code (Z12.11) MUST remain the primary diagnosis to ensure the patient’s preventive benefits are applied. The polyp finding is secondary.
• Medicare G-Codes: Remember that Medicare uses specific HCPCS codes for normal screenings (G0121 for average risk, G0105 for high risk). If the screening turns diagnostic, you drop the G-code and use the therapeutic CPT (e.g., 45385) with modifier -PT.

---

🔗 Related Notes

• 45380 — Colonoscopy with biopsy, single or multiple
• 45385 — Colonoscopy with removal of tumor(s)/polyp(s) by snare technique
• 43235 — EGD, diagnostic (upper GI counterpart)
• Z12.11 — Encounter for screening for malignant neoplasm of colon
• Z86.010 — Personal history of colonic polyps
• K62.5 — Hemorrhage of anus and rectum
• K57.30 — Diverticulosis of large intestine without bleeding

---

_{AMA CPT Codebook 2025 · CMS Physician Fee Schedule Final Rule 2025 · CMS National Correct Coding Initiative (NCCI) Policy Manual · ICD-10-CM Official Guidelines for Coding and Reporting FY2025 · AAPC CPC/CIC Coding Reference}