Cough and Pertussis Swab

Recently we had a patient that had a cough. Almost 2 weeks had passed and the cough hadn't gone away. The doctor instructed the patient to come in and have a swab done for Pertussis. The only service done on that day was the culture. We coded CPT® 87798 for the lab (this is the procedure our outisde vendor conducted). My question is about the diagnosis. Would we use cough as the diagnosis (pertussis swab came back negative) for billing this lab? Or, is there a more appropriate diagnosis we should have used? Thank you.

re: Cough and Pertussi Swab

The cough is the reason for the diagnostic test and thus appropriate

re: Cough and Pertussi Swab

Could you also use the V74.8 diagnosis. The insurance we billed the 87798 won't cover with the cough diagnosis. They state this procedure is "experimental/ investigational".

re: Cough and Pertussi Swab

"Probable," "Suspected," and "Rule Out" Diagnoses

In the outpatient setting (including physician offices), diagnoses documented as "probable," "suspected," "questionable," or "rule out" should not be coded as if they are established. Rather, the conditions should be coded to the highest degree of certainty for that encounter, such as symptoms, signs, abnormal test results, or other reason for the visit. For example, if the physician documents "fever and cough, possible pneumonia" at the conclusion of an emergency room visit, only the fever and cough should be coded, because those symptoms represent the highest degree of certainty for that encounter. However, if the physician documents "fever and cough, possible pneumonia" on a requisition for an outpatient chest x-ray, and the radiologist's diagnosis on the radiology report is "pneumonia," it is appropriate to code the pneumonia, as this diagnosis represents the highest degree of certainty for the encounter for the x-ray. Based on Coding Clinic for ICD-9-CM 17, no. 1, it is appropriate to code based on the physician documentation available at the time of code assignment.

In the inpatient setting, if a diagnosis documented at the time of discharge is qualified as "probable," "suspected," "likely," "questionable," "possible," or "rule out," the condition should be coded as if it existed or was established. The basis for this guideline are the diagnostic workup, arrangements for further workup or observation, and initial therapeutic approach that correspond most closely with the established diagnosis.