By Cyber Sense Billing Team · Published · Updated
Why technique drives colonoscopy coding
A colonoscopy that finds polyps can be coded several different ways depending on how the endoscopist removed or sampled each lesion. CPT distinguishes biopsy, removal by hot biopsy forceps, removal by snare technique, and ablation, and each has its own code. When multiple techniques are used during one procedure, more than one code may apply. When one technique is used on several lesions, the code is usually reported once. Correct coding therefore depends on a procedure report that describes each lesion, its location, size when available, and the technique used. Vague phrases such as polyps removed leave the coder unable to assign the right codes.
The main codes
A diagnostic colonoscopy without intervention is reported with 45378. Biopsy, single or multiple, is reported with 45380. Removal of tumors, polyps, or other lesions by hot biopsy forceps is reported with 45384, and removal by snare technique with 45385. Ablation of lesions not amenable to removal by other techniques is reported with 45388. Other codes describe submucosal injection, control of bleeding, placement of clips, dilation, and stent placement. Because 45378 is the base procedure, it is not reported separately when a therapeutic colonoscopy code is billed. The CPT descriptors and NCCI manual should be consulted for the current definitions.
Multiple lesions and multiple techniques
When several polyps are removed with the same technique, the corresponding code is generally reported once, regardless of how many lesions were removed. When different techniques are used on different lesions, each distinct code may be reported, with the multiple endoscopy payment rules applied by Medicare and many commercial payers. If biopsy and snare removal are performed on the same lesion, only the removal is reported. When a biopsy is taken from one lesion and a separate lesion is removed by snare, both may be reported, and a modifier such as 59 or XS may be needed to show distinct lesions.
When screening becomes therapeutic
Colonoscopies scheduled as screening often become therapeutic when a polyp is found. For Medicare, the procedure is reported with the therapeutic code and modifier PT, which signals that a screening became diagnostic or therapeutic and keeps the Part B deductible from applying. Coinsurance has historically applied in these cases, and Medicare has been phasing that coinsurance down under federal law, so confirm the current percentage for the date of service. Commercial payers often use modifier 33 to indicate preventive intent. The screening diagnosis code should be listed first, followed by the finding.
Documentation that supports the claim
A complete procedure report includes the indication, the type of preparation and its quality, extent of examination with cecal landmarks, withdrawal time when tracked, each lesion's location and approximate size, the technique used for each, retrieval status, any complications, and the plan. When specimens are sent to pathology, labeling should match the report so pathology results can be linked to the correct lesion. Consistent templates make coding faster and reduce queries to physicians.
Pathology and diagnosis coding
Diagnosis codes for polyps depend on the pathology result. Many practices hold colonoscopy claims until pathology is available so the diagnosis reflects whether a polyp was adenomatous, hyperplastic, or malignant, while others code from the procedure report using finding-based codes. Either approach can work if applied consistently and in line with coding guidelines. Holding claims should not delay them beyond timely filing limits, so set a maximum hold period.
Common denials and how to avoid them
Frequent issues include billing 45378 together with a therapeutic code, missing the PT or 33 modifier on a converted screening, reporting the same code multiple times for multiple polyps, inadequate documentation of technique, and diagnosis sequencing that loses the screening intent. Pre-claim review of colonoscopies with interventions, against the procedure report and pathology, catches most of these errors before submission.
Frequently asked questions
Is an incomplete colonoscopy coded differently?
Yes. Incomplete procedures may need a reduced or discontinued service modifier depending on the reason and payer rules. Document how far the scope advanced and why the procedure stopped.
What modifier shows that two lesions were treated differently?
Modifier 59, or the more specific XS for a separate structure or site, is commonly used when NCCI edits pair the codes. Use it only when the report clearly shows distinct lesions and follow each payer's modifier preferences.
Should we wait for pathology before billing?
Many GI practices do, so the diagnosis reflects the final pathology. Set a maximum hold time, such as a set number of days, so claims are not delayed past timely filing limits when pathology is slow.
How many times do we bill 45385 if three polyps were snared?
Generally once. The snare code describes removal of one or more lesions by snare technique during the same procedure.
Can 45380 and 45385 be billed together?
Yes, when the biopsy and snare removal were performed on different lesions. Use the appropriate modifier to show distinct lesions.
Does the patient owe anything when a screening becomes therapeutic?
For Medicare, the deductible is waived with modifier PT, but some coinsurance may apply depending on the year. Commercial cost sharing depends on the plan.
Sources and further reading
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This article is general information, not legal or coding advice. Always check current CPT®, ICD-10-CM, CMS and payer guidance. Questions? Contact us.