Diagnosis Coding for Screening Colonoscopy

Some of you have read CodingIntel’s article on coding for screening colonoscopy.  The questions we get about that article are almost all related to diagnosis coding.

The CPT^®/HCPCS coding and the modifiers don’t raise many questions but clinicians, coders, and patients frequently ask about correct diagnosis coding and sequencing of those codes.

We recently posed these questions to our friend and colleague, Margaret Skurka, MS, RHIA, CCS, FAHIMA who is an expert on ICD-10 coding.

First, the citation from the General Guidelines in ICD-10, then on to the Q&A.

I 21 c Screening is the testing for disease or disease precursors in seemingly well individuals so that early detection and treatment can be provided for those who test positive for the disease (e.g., screening mammogram).

The testing of a person to rule out or confirm a suspected diagnosis because the patient has some sign or symptom is a diagnostic examination, not a screening. In these cases, the sign or symptom is used to explain the reason for the test.

A screening code may be a first-listed code if the reason for the visit is specifically the screening exam. It may also be used as an additional code if the screening is done during an office visit for other health problems. A screening code is not necessary if the screening is inherent to a routine examination, such as a pap smear done during a routine pelvic examination.

Should a condition be discovered during the screening then the code for the condition may be assigned as an additional diagnosis.

ICD 10 General Guidelines, page 96: https://www.cms.gov/files/document/fy-2025-icd-10-cm-coding-guidelines.pdf

Question 1 | Sequencing

Q: If a test is scheduled as a screening (colonoscopy) and a polyp is found, how should these be sequenced?

For example:

• Z12.11 encounter for screening for malignant neoplasm of colon
• K63.5 polyp of colon

A: The screening code (Z12.11) would go first followed by any findings.

Citation: ICD-10-CM/PCS Coding Clinic, First Quarter ICD-10 2017 Page 8 Effective with discharges: March 13, 2017 states that whenever a screening examination is performed, the screening code is the first-listed coded.  The fact that the test is a screening remains, regardless of the findings or any additional procedure that is performed as a result of the findings.

Remember that once the polyp is removed, the patient follow-up visits should not be coded with K63.5, polyp of colon.  At that time, it is appropriate to use code Z86.010X, personal history of colonic polyps. (Beginning October 1, 2024, Z86.010- requires a 7^th character.)

Question 2 | Surveillance colonoscopy

Q: What if it is a surveillance colonoscopy, four years later. Then, what diagnosis coding is used? Can I still use Z12.11 on the claim form, or only Z86.010 personal history of colonic polyps?  If I can use both, is there a rule about sequencing?

A: Words that physicians may use for screening colonoscopies include screening, surveillance, preventive, high risk screening, average risk screening, need for screening, etc. In this case, since the word SURVEILLANCE colonoscopy is documented, I would recommend coding this as a screening (Z12.11), followed by any findings, as well as the personal history of colonic polyps (Z86.010) – sequenced in that order.

Question 3 | Family history

Q:  And what about a patient with a family history of colon cancer?

A: Of note, if there is only a diagnosis of FAMILY history of colon cancer and nothing else is documented, these are coded as a screening (even if the physician doesn’t document screening).  This is based on a Coding Clinic, 1999, 1st qtr. page 4.

Here is the citation from the ICD-10-CM and ICD-10-PCS Coding Handbook regarding screening examinations:

“Codes from categories Z11-Z13, Encounter for screening, are assigned to encounters for tests performed to identify a disease or disease precursors for the purpose of early detection and treatment for patients who test positive.  Screening is performed on apparently well individuals who present no signs or symptoms relative to the disease.  A screening mammogram is an example of such a test.  If a screening examination identifies pathology, the code for the reason the test (namely, the screening code from categories Z11-Z13) is assigned as the principle diagnosis or first-listed code, followed by a code for the pathology or condition found during the screening exam.”

Many, many thanks to Margaret Skurka and her colleague who answered these questions and included the citations. Here is a link to her linkedin profile https://www.linkedin.com/in/margaret-skurka-b643aa6/.

Members can also access the full article – Procedure Coding for Colonoscopies, or watch a short video Reporting Screening Colonoscopy

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