Gastroenterology Coding Alert

Question: A patient under the age of 45 came in for a colonoscopy due to a family history of colon cancer. Should I be using the screening or the history as the primary diagnosis? Do I need to also use modifier 33 on the procedure? I’ve had similar claims denied, and I’m not sure why.

AAPC Forum Participant

Answer: Generally, if a preventative colonoscopy screening is the reason for the encounter, the screening itself would be sequenced first, followed by the family history, per ICD-10-CM Official Guidelines I.C.21.c.4. Appending modifier 33 (Preventive services) to the procedure code would not be necessary though.

Before explaining further, it’s important to note that if the documentation doesn’t describe this as a preventative screening and only mentions the patient’s age, family history, and the recommendation, it’s best to confirm with the practitioner that this is a screening and not a diagnostic test. If the patient presented with signs and symptoms that raised some red flags, you’d need to code to the signs and symptoms.

If the practitioner’s notes are clear about this encounter being a preventative screening, and the reason for the visit is that exam, it is correct to code the screening first using Z12.11 (Encounter for screening for malignant neoplasm of colon), followed by any applicable personal or family history Z codes, per ICD-10 guidelines I.C.21.c.4 and I.C.21.c.5. For the encounter described, that would mean reporting Z80.0 (Family history of malignant neoplasm of digestive organs).

For the colonoscopy procedure, you’ll choose one of the codes between 45378 (Colonoscopy…) and 45398 (Colonoscopy, flexible; with band ligation(s) (eg, hemorrhoids)), depending on which technique the provider used.

Tip: For instruction on whether to use modifier 33, turn to CPT^® Appendix A, which describes each modifier and its use. It states: “For separately reported services specifically identified as preventative, the modifier should not be used.” However, if a screening turns diagnostic, Medicare requires the use of modifier PT (Colorectal cancer screening test; converted to diagnostic test or other procedure) after the procedure code. For example, that would mean reporting 45385-PT (Colonoscopy, flexible; with removal of tumor(s), polyp(s), or other lesion(s) by snare technique) if the provider began the procedure as a screen, then discovered and removed tumors, polyps, or lesions from the patient’s colon using a snare technique. In instances such as this, the primary diagnosis will still be Z12.11.