A colonoscopy prompted by a positive Cologuard test is not a diagnostic procedure. This Coding Tip explains how coding guidance has evolved, why current Medicare policy considers a follow-on colonoscopy a continuation of the colorectal cancer screening process, and how that impacts ICD-10-CM diagnosis coding. You'll learn when to report Z12.11 as the primary diagnosis, when to assign R19.5 as a secondary diagnosis, and why modifier KX is important for follow-on screening colonoscopies after a positive Cologuard test.
The Cologuard® and Cologuard Plus™ tests are intended to screen adults 45 years of age and older who are at average risk for colorectal cancer by detecting certain DNA markers and blood in the stool.
False positive and false negative results of a Cologuard test can occur, therefore a positive Cologuard test result does not confirm the presence of cancer. Patients with a positive test result should be referred for colonoscopy. A negative test result does not confirm the absence of cancer. Patients with a negative test result should discuss with their doctor when they need to be tested again.
Medicare and other payers consider a Cologuard test a screening exam covered as a preventive service with waiver of patient responsibility in relation to copayment, coinsurance and deductible. For patients with a positive Cologuard result for whom a colonoscopy is recommended to make a definitive determination of the presence or absence of colon cancer, the question becomes whether the diagnosis coding on the claim for the colonoscopy should indicate performance of another screening exam, which could be an issue because payers typically only cover screening exams on a specific schedule of frequency, or a diagnostic exam. The advice around ICD-10-CM code selection for these cases has changed over time as follows.
In 2019, ICD-10-CM/PCS Coding Clinic, First Quarter ICD-10 2019 Page: 32 advised reporting R19.5, Other fecal abnormalities as the primary diagnosis for a colonoscopy performed because of a positive Cologuard test.
Additionally, ICD-10-CM/PCS Coding Clinic, First Quarter ICD-10 2019 Page: 33 indicates that when a colonoscopy is performed due to a positive finding on a Cologuard test, the colonoscopy would be considered a diagnostic examination, not a screening.
Based on direction in ICD-10-CM coding guidelines I.C.21.c.5 and IV. K, this advice seems to make sense because the reason for the colonoscopy is the abnormalities found in the results of the Cologuard test.
However, this advice does not take into account that the patient’s screening experience started with a test whose results, when positive, are suggestive of but not definitive for colon cancer, necessitating a continuation of testing for confirmation. This begs the questions, “Can a patient be considered fully screened for a condition if the condition has not been definitively ruled out?”
In 2022, Coding Clinic for HCPCS - Fourth Quarter 2022 Page: 17 released advice that seems to address the question above. This coding clinic states, in part:
“…Effective Jan. 10, 2022, the Biden Administration released guidance requiring private insurers to cover a follow-up colonoscopy after an abnormal/positive stool-based test as a preventative service. The follow-up colonoscopy is considered a continuation of the preventative service. Any concerns on correct reporting should be directed to the individual payer.
Effective Jan. 1, 2023 Medicare coverage policies for colorectal cancer screenings will change. Specifically, as specified in 42 CFR 410.37(k), for dates of service on or after Jan. 1, 2023, colorectal cancer screening tests include a follow-on screening colonoscopy after a Medicare covered non-invasive stool-based colorectal cancer screening test returns a positive result. Therefore, when a Medicare patient presents for a follow-up colonoscopy due to a positive stool-based colorectal cancer-screening test, the colonoscopy would be a continuation of the preventative service and not considered a diagnostic exam.”
The ICD-10-CM coding guideline I.C.21.c.5 directs the use of a screening Z code as the first-listed code if the reason for the visit is specifically a screening exam. So, based on the specification of the follow-on colonoscopy after a positive Cologuard test as a screening colonoscopy the correct diagnosis code to assign to support this procedure is Z12.11 Encounter for screening for malignant neoplasm of colon. Code R19.5 should be assigned as a secondary code to support the need for the follow-on screening colonoscopy.
Some coders may feel compelled to follow the 2019 advice from Coding Clinic directing assignment of R19.5 as the primary diagnosis for these cases. However, it appears the earlier advice in Coding Clinic for ICD-10-CM/PCS was not updated as was the later advice in Coding Clinic for HCPCS to reflect the changes in regulatory requirements since the ICD-10-CM coding guidelines direct assignment of a screening Z code for screening exams and the coding guidelines take precedence over the advice in Coding Clinic.
Medicare also has multiple references that provide direction related to this issue.
For example, the Medicare Learning Network article, Removal of a National Coverage Determination & Expansion of Coverage of Colorectal Cancer Screening states,
“Also, a positive result from a non-invasive stool-based CRC screening test no longer requires that the following colonoscopy be a diagnostic colonoscopy. CRC screening tests now include a follow-on screening colonoscopy after a Medicare-covered, non-invasive, stool-based CRC screening test returns a positive result (within the context of a complete colorectal cancer screening). We now understand both the non-invasive, stool-based test and the follow-on colonoscopy are both part of a continuum of a complete CRC screening. Patient cost sharing won’t apply to the non-invasive, stool-based test and the follow-on screening colonoscopy in the scenario of a complete colorectal cancer screening, because both are specified preventive screening services. In addition, frequency limitations for screening colonoscopies in 42 CFR 410.37(g) won’t apply to the follow-on screening colonoscopy in the context of a complete colorectal cancer screening.
…When you provide a screening colonoscopy in the context of a complete colorectal cancer screening (following a positive result from a non-invasive stool-based CRC screening test), the providing practitioner must apply the -KX modifier to the claim for the screening colonoscopy to confirm that the clinical requirements of the complete colorectal cancer screening policy are met.”
Please visit MM13017 - Removal of a National Coverage Determination & Expansion of Coverage of Colorectal Cancer Screening for a full review of Medicare’s information regarding this topic.
Medicare Administrative Contractor Noridian also provides similar advice to the providers they cover. The direction on their website says,
Screening colonoscopy following a positive result from non-invasive stool-based CRC screening test
Please visit Colorectal Cancer Screening - JF Part B - Noridian for a complete review of the relevant guidance from Noridian.
Both the advice in the Medicare Learning Network article and from Noridian indicate appending HCPCS modifier KX to the claim for a follow-on screening colonoscopy after positive Cologuard test. The long description of HCPCS modifier KX is “Requirements specified in the medical policy have been met”.
When this modifier is added to a claim, it signifies that the documentation supports the service as reasonable and necessary, meeting specific medical necessity requirements set by the payer, typically Medicare.
Appending this modifier to the CPT code for a colonoscopy that follows after a positive Cologuard test indicates the documentation supports billing the procedure as a screening procedure, not diagnostic, because it is a continuation of a preventive service.
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The information contained in this coding advice is valid at the time of posting. Viewers are encouraged to research subsequent official guidance in the areas associated with the topic as they can change rapidly.