Quick Answer: CPT Code for Colonoscopy
The CPT code for colonoscopy without biopsy or therapy is 45378. Use code 45380 for biopsy and 45385 for snare polyp resection. Usually, Medicare screening colonoscopies without intervention are reported using code G0121 or G0105. The final code assignment is based on the detailed description of the service performed, the reason for the service, the payer’s requirements, and whether the service was performed in an adequate manner
Choose the CPT code for colonoscopy from the procedure note
Examine the signed procedure report first. Sometimes the information on the scheduled service form gets completed by the end of the case, but not always.
The physician may have taken a biopsy, removed a lesion, or stopped a bleeding site. If a lesion was removed, it may have been biopsied and/or sent for pathology. If bleeding was stopped, the site may have been treated with a form of therapy (e.g. injection, banding, etc.) or cauterized.
| Code | Plain-language service | Key distinction |
|---|---|---|
| 45378 | Diagnostic colonoscopy; may include brushings or washings | Tissue biopsy and treatment require their appropriate procedure codes |
| 45380 | Colonoscopy with biopsy, single or multiple | Commonly applies to cold-forceps tissue sampling |
| 45385 | Colonoscopy with snare removal of lesion(s) | Includes cold or hot snare technique |
| G0121 | Medicare screening colonoscopy, not high risk | HCPCS Level II code, not a CPT code |
| G0105 | Medicare screening colonoscopy, high risk | Document the qualifying risk history |
| 45384 | Lesion removal with hot biopsy forceps | Don’t confuse hot forceps with hot snare |
| 45382 | Endoscopic bleeding control | Not automatically reportable for bleeding caused by another intervention |
| 45390 | Endoscopic mucosal resection | Review its included services before adding other codes |
Some codes represent specific techniques. For example, 45388 represents ablation. Other codes, such as 45379 and 45381, represent the removal of foreign bodies and submucosal injections, respectively. Some codes represent procedures performed using special equipment. For instance, codes 45389, 45391, and 45392 represent the placement of certain types of endoscopic stents and the performance of ultrasound procedures and endoscopic decompression, respectively.
Because a code may appear to represent a more lucrative service, some may be tempted to assign that code to the related service merely based on authorization. This should be avoided. The full description of the code in question should be reviewed to determine if it is indeed supported by the documented service.
The route of the procedure may also impact the code assigned to the service. A procedure performed on the distal ileum may not always justify assignment of the code for ileoscopy. The same may hold true for procedures performed on other areas of the GI tract.
Full description of terms used in this text may be found in code definitions.
Screening, diagnostic and surveillance: start with the indication
The reasons for the examination and the work performed are distinct from each other. However, both should be shown in the course of adjusting a claim.
| Category | Reason for examination | Coding approach | Benefit question |
|---|---|---|---|
| Screening | Preventive examination without symptoms prompting the procedure | Apply the payer’s screening pathway; report an intervention if performed | Is this a covered preventive service under this plan? |
| Diagnostic | Evaluation of symptoms, disease or another diagnostic indication | Report the documented examination or intervention and supported diagnosis | Which diagnostic deductible and coinsurance rules apply? |
| Surveillance | Follow-up because of prior polyps, colorectal cancer or another relevant history | Review the clinical indication, risk criteria and payer’s surveillance policy | Does this payer process the examination as high-risk screening or another benefit? |
Screening intent can remain relevant after a polyp is removed
Polyp removal often requires a screening test. Just because a polyp was removed during a screening test doesn’t mean the indication for the screening test was removed as well. The indication may affect the preventive modifier and how the payer recognizes cost sharing.
Additionally, finding a polyp does not make a symptom-related examination a screening examination. For example, if there was an order for an examination to evaluate rectal bleeding, the documentation should reflect that order and purposes, and should not be changed to reflect a screening examination merely because a polyp was found during the examination.
Surveillance carries a greater responsibility than merely documenting history
When documenting history, it is critical to determine what, if any, prior pathology is captured on the record, the date of the last intervention, and the interventional specialist’s recommendations.
Often, coverage and clinical decisions are impacted by the rationale provided for the recommendation of a particular course of action.
In the absence of other defined rules, i.e. “blanket rules,” it is assumed that a case-by-case evaluation is being conducted. Therefore, assumptions regarding the reason’s for categorization should not be made.
Guidelines, recommendations, and scope of coverage are impacted by a multitude of factors. The case-specific details are critical for the interpretation of the guideline and the determination of scope of coverage. A scheduling directive alone provides little to no context for coverage or clinical rationale.
Medicare and commercial plans follow different claim paths
Original Medicare: begin with the screening G codes
When a patient does not meet the high-risk criteria, the covered screening colonoscopy can be reported with G0121. If a patient meets high-risk criteria, the same procedure can be reported with G0105. Biopsy or other interventions are reported with the appropriate CPT code, in addition to the G code. The G code is not to be assigned and paid for the same service.
Screening colonoscopies are covered by Original Medicare for high-risk patients every 24 months. Colonoscopies are covered for patients not at high-risk every 120 months, with a screening flexible sigmoidoscopy in the previous 48 months. There is no minimum age for the Medicare benefit.
For 2026, Medicare will pay 85% of the agreed upon amount for the Screening Colonoscopy, and 85% of the agreed amount for the Outpatient Facility. There will be no Part B deductible for Screening Colonoscopies.
Commercial plans: verify the preventive claim instructions
There are specific guidelines commercial plans use for reimbursement of preventive screening. Plan language is essential to correctly analyze a preventive service. The documentation must also indicate whether there was a biopsy or snare removal performed. Keep in mind the plan’s preventive language to determine appropriate code and diagnosis.
Practice specialty guidance and workflows taught in Medicare PT will not apply to the same extent to other payer types. Verify the payer’s plan document, network status and billing instructions specific to the payer. The same is also true for Medicaid plans.
If you are documenting coverage for a service that would otherwise be considered not medically necessary, capture the name of the policy as well as the date and a summary of the rationale. This will ensure that the next reviewer is not left without justification should they have to defend coverage for the service again.
A positive screening test doesn’t automatically mean diagnostic billing
If a beneficiary receives a covered noninvasive colorectal screening test and the result is positive, Medicare will cover a qualifying follow-on colonoscopy. Qualifying follow-on screening is defined by CMS and implemented by KX. This pathway defines qualifying tests as stool-based and blood-based tests. The effective and eligibility dates are also determined by this pathway.
Prior test reports should be retained. KX should be used only when there is agreement on the test and the result. When there is agreement on the result, but the procedure is not covered, a procedure code should be determined and assigned along with the appropriate modifier, rather than assuming KX excludes PT.
Modifiers that change how the claim is processed
Modifiers explain circumstances. They don’t supply missing documentation or make a bundled service independently payable.
| Modifier | Practical purpose | Check before using it |
|---|---|---|
| 33 | Identifies an applicable preventive service | Commercial plan requirements and original indication |
| PT | Identifies a colorectal screening test converted to another procedure | Medicare instructions and the intervention performed |
| KX | Identifies a qualifying follow-on screening colonoscopy | Prior covered screening test and current CMS requirements |
| 53 | Discontinued procedure on the professional claim, when supported | Extent reached, reason stopped and procedure-specific guidance |
| 73 | Certain discontinued hospital outpatient/ASC procedures before anesthesia | Facility rules and the documented stage of care |
| 74 | Certain discontinued hospital outpatient/ASC procedures after anesthesia or procedure initiation | Facility rules; do not automatically copy onto the professional claim |
| 59 / XS | Distinct services in supported circumstances | Current edit, modifier allowance and separate-lesion documentation |
There may be similar circumstances described by the professional and facility claims with different sorts of modifiers. CMS’s Guidance on Incomplete Colonoscopy differentiates reporting from discontinuance by stating, “If a physician orders a colonoscopy to be performed and the physician leaves the facility before the procedure is completed, the physician would report the Colonoscopy”.
When the examination isn’t completed
Document the extent of the scope. The rationale for stopping the examination should also be documented. Generally, “poor prep” is not as informative as documentation that describes the limit to which the examination was made and the rationale for stopping the examination.
Blindly changing an incomplete colonoscopy code to a sigmoidoscopy code is not appropriate. Similarly, adding a 53 modifier to every therapeutic endoscopic procedure that did not reach the cecum is also inappropriate. Each situation should be evaluated to determine what the intended examination was and if a reduced service was provided and/or CPT and payer editing directions were met for the service provided. A reduced service, modifier 52, may be appropriate in some situations; however, this should be confirmed.
An administrative, or other type, of cancellation that occurs prior to the provision of the service, should not be reported as a discontinued service. There are situations when discontinuation of a service does occur. The situation and the reasons for discontinuation should be documented. This includes the timing of anesthesia, if provided.
Biopsy and polyp removal: the technique matters
Here’s where a short procedure description can cause trouble: “polyp removed” doesn’t identify the removal technique.
Cold Forceps, Hot Forceps and Snare are different
Removal of colon polyps using cold forceps would be appropriate with code 45380. On the other hand, performing a hot biopsy using hot forceps would be appropriate with code 45384. Removing polyps using snare, either hot or cold, is appropriate with 45385. Polypectomy merely describes the removal of a colon polyp and code selection is not warranted in this situation.
If the description of the procedure is unclear, ask the clinician for additional information in a query stating, “Clarification of sigmoid lesion removal required.” Do not encourage the clinician to describe a more complicated or invasive procedure.
The removal of a single polyp does not warrant the assignment of two or more units of a particular code. Review the applicable language of the descriptional list and prescribed limitations to determine when more than one unit of a code may be appropriate.
When analyzing the same or multiple lesions
After a lesion is biopsied, it is often removed by snare polypectomy. In this scenario, the biopsy is considered part of the removal and is not reported separately. If another lesion is biopsied, then reporting an additional biopsy would be acceptable if done in accordance to the current edit and appropriate modifier.
When a biopsy or snare polypectomy is performed, location of the lesion is reported, as well as the method (snare vs. biopsy). Additional reporting is warranted when the lesion is in a different location and the methodology used is different. In this scenario, modifier 59 is appropriate to report the service as an additional, distinct service.
When a polypectomy is performed to stop bleeding from a prior endoscopic mucosal resection, the bleeding control is considered part of the prior polypectomy and not reported. Likewise, a biopsy performed as part of a diagnostic scope or surgical endoscopy is considered part of the scope and not reported.
Link the diagnosis without rewriting the history
In CPT coding, the type of service is reported, and in ICD-10-CM coding, the nature of the condition is reported. A valid service code does not guarantee a valid claim when submitted with an incorrect diagnosis code.
- Z12.11 signifies a malignant colon cancer screening.
- To support a diagnosis code request, the documentation must describe a condition or symptoms.
- To code personal or family history, the clinician must document the history and the code must reflect the history as accurately as possible.
- “Polyp” is a very general term. If the term “polyp” is documented, the coding professional should not assume that the polyp is malignant or an adenoma.
In the 2024 edition of the ICD-10-CM, the history code Z86.010 for “Personal history of colon polyps, unspecified” was divided into four codes: Z86.0100 for unspecified colon polyps, Z86.0101 for adenomatous and serrated colon polyps, Z86.0102 for hyperplastic colon polyps, and Z86.0109 for other colon polyps. The code should be assigned based on the service date.
If a polyp is found during a colon cancer screening, and malignancy is ruled out, the screening diagnosis should not be deleted. If the documentation follows payer and diagnosis sequence rules, a claim should not be rejected.
Separate services: anesthesia, pathology and CT colonography
Anesthesia has its own code selection
The endoscopist’s procedure coding does not impact the reporting of anesthesia. Codes 00811 and 00812, respectively, describe anesthesia for lower GI endoscopy and anesthesia for screening colonoscopy. Code 00813 describes anesthesia for an upper and lower GI endoscopy.
Generally, prevention of an intervention is presumed when anesthesia is reported with a preventive modifier. When an endoscopic procedure becomes diagnostic or therapeutic, both the modifier and anesthesia code would need to be assigned, independently of each other. An endoscopist’s 45385 code line does not describe the anesthesia medical billing services reported, and therefore should not be used in coding the anesthesia service.
Provider role modifiers indicate a variety of potential services. For example, QZ describes a CRNA’s service, not the service of an anesthesiologist. In the case of the modifier documenting anesthesia, it should be coded according to the provider arrangement and the applicable rules for reimbursement.
Pathology and facility charges need their own explanation
Patients may receive multiple statements from various providers. This can include the endoscopist, the facility, the anesthesia provider, and the pathology laboratory. Prior to the appointment, explain this to the patient and provide the expected providers and plan information.
Staff should not assume that the cost of the colonoscopy will be the only cost associated with the procedure and therefore not estimate the procedure to be the entire episode. Similarly, staff should not guarantee to the patient that the pathology charges will be out-of-pocket costs. Pathology charges may be covered by the patient’s benefit. As always, charges may vary based on the patient’s insurance plan and benefit level.
Patients should be aware that they have the right to request an itemized statement and compare it to their Explanation of Benefits.
Virtual colonoscopy uses radiology codes
Diagnostic imaging performed via CT colonography is evaluated and reported using codes 74261, 74262 and 74263, based on whether the study is performed without contrast, with contrast, or as a screening study, respectively. CT colonography does not report the use of optical colonoscopy, biopsy or snare codes.
Mederic now reimburses eligible screening CT colonographies. The Medicare rules regarding age and frequency of screening CT colonographies differ from optical colonoscopy screens, and Medicare will reimburse CT colonography screening beginning at the age of 45. Older articles stating that Medicare will never cover CT colonography screening are inaccurate.
Six coding scenarios to test the claim
These are hypothetical teaching examples, not patient cases or promises of reimbursement. Each assumes supporting documentation and requires current payer verification.
1. Average-risk Medicare screening, no intervention
The beneficiary has an annual screening exam. A biopsy or removal is not performed. Report this code when the high-risk criteria are not met. Prior to releasing, review the prior screening interval and the indicated reason for the screening.
2. Medicare Screening with Cold-Snares
This code describes a screening colonoscopy. The procedure also includes the removal of a polyp using a “cold snare” technique. Report 45385 along with the lowest time PT. Also do not report G0121 for the same procedure. Cold snare removal preserves the original indication. Provide additional diagnosis as directed by the payer.
3. Symptomatic patient with biopsies
The patient had colonoscopy with multiple biopsies done for chronic diarrhea. The biopsies have been done to look for colonic causes of diarrhea. Review the case with the supported diagnosis. As the biopsies were done to evaluate the colonic causes of the patients’ symptoms, it can not be said that multiple samples equate to multiple procedures. Preventive modifier doesn’t apply in cases where a patient is screened due to age.
4. Removal of lesion by snare and biopsy at other site
A lesion is removed by snare, and a separate lesion is biopsied. Review the edit to determine if a distinct service modifier is permitted. If a modifier is permitted, edit to report the services separately. If no modifier is permitted, determine if the report distinguishes the lesions. If the report does not distinguish the lesions, request clarification before reporting the services as separate.
5. Qualifying follow-on screening after a positive test
A Medicare beneficiary arrives for an evaluation after having undergone a positive non-invasive screening test that is covered by Medicare. Evaluate to see if the conditions for the follow-on screening have been met, and if so, complete the required report to KX. A “positive” screening test does not, in and of itself, classify the screening test as being medical necessary. It may be necessary to review the entire covered screening pathway in order to classify the test as being medically necessary.
6. Examination stopped before completion
The physician stopped the service because continuing presented a risk to the patient. Record the reason and extent of the service stopped. Also, record the reason against professional judgment for service discontinuation. Additionally, the facility will determine if their documentation supports Code 73 or Code 74. The choice of a particular modifier is facility specific and should not be generalized.
Catch billing mistakes before the claim leaves
A practical review consists of going through each step from answering the call to preparing the final report, as opposed to looking at each portion as a data-entry job in and of itself.
| Mistake | Better pre-submission check |
|---|---|
| Every colonoscopy defaults to 45378 | Read the final intervention and technique |
| Screening intent disappears after removal | Compare the original indication with the final claim |
| Modifier 33 replaces payer research | Confirm the plan’s preventive instructions |
| Two techniques on one lesion become two payable services | Review lesion identity and bundling |
| Old history codes remain in a template | Validate codes against the service-date edition |
| Professional and facility modifiers are copied | Review each claim type independently |
| A universal reimbursement figure is quoted | Use the applicable fee schedule or contract and setting |
Build a documentation checklist that answers coding questions
Prior to submission, review the reason for examination, relevant history, previous examinations, extent of preparation, limitations of preparation, findings, anatomic location of lesions, interventional radiology procedures and the reason for the procedure was stopped, if applicable. Reconstruct the pathology work-up if it aids in forming the final diagnosis.
For interventional radiology cases, one way to check the quality of case documentation is to determine if the case report documentation enables a second reviewer to identify the case intervention without the need to inquire which of the many lesions the case report interventional radiology procedure was performed to address. This type of quality check has been shown to identify deficiencies in documentation prior to a claim being submitted for reimbursement.
Work a denial from the actual reason
Review the remittance advice and identify the disputed line. Issues may include, but are not limited to, eligibility, frequency, authorization, diagnosis and/or supporting evidence, bundling and missing modifiers. Based on your determination, review the claim, the original record and the payer’s current/relevant Edits, Policies and/or Guidelines.
Pursue an appropriate appeal of a supported coverage/reimbursement decision. Do not amend the claim to add/remove symptoms or alter the screening reason/limiting amendments. Likewise, do not add a distinct service modifier.
There are templates for different denial reason codes to assist with the required documentation for the ongoing appeal. Claims should not be regularly amended to indicate a denial has been resolved.
On an ongoing basis, review templates and denials to ensure they remain current and relevant to the overall billing needs of the organization.
Keep benefits checks connected to the final claim
Record the expected indication, prior examination date, anticipated location, and any required authorization prior to the appointment. If surveillance is the expected reason for the appointment, ask about that specifically. Other, more general, questions about things like “colonoscopy coverage” may not clarify the reason for the appointment and the benefits associated with it.
After the appointment, review the signed report to determine what indication was ultimately given. Provide both the coding and medical billing services divisions with the expected indication. The Coding division needs to know the expected indication to determine the proper code to assign to the procedure. Give both divisions the expected indication.
When providing a patient with an expected cost of a service, tell the patient that it is an estimate and give the expected service date. Provide the expected cost based on the patient’s health plan, the expected service providers, and the expected service location. The expected service location may vary based on the health plan. Health plans may exclude specific service locations.
If a health plan denies a request for service, a patient may be entitled to an appeal. Provide the patient with a copy of the appeal, the health plan’s denial, and the expected evidence to support the request. This may help the patient determine the reason for the health plan’s denial without requiring the patient to provide the health plan with a large number of unrelated records.
Frequently asked questions
What is the CPT code for a routine colonoscopy?
45378 describes a colonoscopy without biopsy or treatment, including brushings or washings when performed. Screening reporting depends on the payer: Original Medicare generally uses G0121 or G0105 when no intervention occurs.
Which code applies to colonoscopy with biopsy?
45380 applies to colonoscopy with biopsy, single or multiple. Check whether the biopsy is included in another procedure on the same lesion before reporting it separately.
Is cold-snare removal coded differently from hot-snare removal?
Both use 45385 when the documented procedure meets the snare-removal descriptor. Cold-forceps sampling and hot-biopsy-forceps removal use different coding pathways.
Can 45380 and 45385 be billed together?
They may be separately reportable for distinct lesions when documentation and current edits support it. A biopsy followed by snare removal of the same lesion generally does not support separate biopsy reporting.
Is surveillance colonoscopy always diagnostic?
No universal rule covers every payer and history. Review the documented indication, prior pathology, risk classification and plan policy. Some examinations may qualify for a high-risk screening pathway.
Does removing a polyp always mean the patient pays?
No. Patient responsibility depends on the plan, covered benefit and other circumstances. Original Medicare’s 2026 rules describe reduced coinsurance when tissue is removed during screening; commercial preventive benefits need separate verification.
Which modifier applies to an incomplete colonoscopy?
Modifier 53 may apply to the professional claim in supported discontinued-procedure circumstances. Facilities use their own rules for 73 or 74. The intended procedure, completed work and reason for stopping determine the review.
