Isolated proteinuria with unspecified morphologic lesion

This code signifies the presence of protein in the urine without an identified underlying kidney structural abnormality. It indicates proteinuria that is not associated with other signs of kidney disease or a specific pathological finding on biopsy.

Apply this code when documentation confirms isolated proteinuria, and a renal biopsy, if performed, does not reveal a specific morphologic lesion. It is appropriate when the cause of the proteinuria remains undetermined after initial workup or when the proteinuria is considered benign or idiopathic.

• Do not use if a specific glomerular or tubular lesion is identified (e.g., focal segmental glomerulosclerosis, membranous nephropathy).
• Ensure documentation explicitly states "isolated proteinuria" or "proteinuria with unspecified morphologic lesion" to support this code.
• Consider sequencing this code as a secondary diagnosis if the primary reason for the encounter is related to monitoring or evaluating the proteinuria.