Completing the UB-04 Claim Form – Introduction Practice Test

On UB-04, the main reason the patient is admitted is captured as the principal diagnosis. Other diagnoses are the additional conditions that exist at admission or develop during the stay and affect how the patient is treated. They’re coded separately to reflect the full clinical picture and can include comorbidities or complications that influence care, resources, and outcomes. For example, a patient admitted for pneumonia might also have diabetes noted as another diagnosis because it affects treatment decisions and monitoring. So the difference is that the principal diagnosis is the primary reason for admission, while other diagnoses are secondary conditions that impact care.