Gastroenterology Coding Alert

Question: Our insurer is now rejecting claims if they see tertiary diagnoses mentioned in the progress note that we haven’t coded on our claims. This usually involves “Z” codes, which we haven’t paid much attention to in the past. We typically only use Z12.11 (Encounter for screening for malignant neoplasm of colon). Which other Z codes should we be using?

Codify Subscriber

Answer: The answer will depend on the conditions that are noted in your progress notes and op reports. Contrary to what some coders believe, you may — and on occasion must — report Z codes as primary diagnoses. “Z codes may be used as either a first-listed (principal diagnosis code in the inpatient setting) or secondary code, depending on the circumstances of the encounter,” the ICD-10-CM manual says. “Certain Z codes may only be used as a first-listed or principal diagnosis.”

One common instance when practices select a Z code as a primary diagnosis is for screening exams. These include several codes that describe screenings for neoplasms, and not just those in the colon (for instance, Z12.0, Encounter for screening for malignant neoplasm of stomach).

You might also use Z codes as primary diagnoses when the gastroenterologist provides care for a patient with current or past injuries and/or treatment, as well as other screening services.

Example: A patient presents for aftercare to address the functionality of an implanted infusion pump. You’ll report Z45.1 (Encounter for adjustment and management of infusion pump) to describe the reason for the visit.

Example 2: A patient presents for a screening for an upper GI disorder. In this case, you’ll report Z13.810 (Encounter for screening for upper gastrointestinal disorder).