O12.12 Gestational proteinuria, second trimester

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.

MS-DRG index

Defines the logic of DRG(s) 817-819 in MDC 14.

Approximate ICD-9-CM (GEMs)

• 646.21 Unspecified renal disease in pregnancy, without mention of hypertension, delivered, with or without mention of antepartum condition (approximate)
• 646.23 Unspecified renal disease in pregnancy, without mention of hypertension, antepartum condition or complication (approximate)

Medicare Code Edits (MCE v43.1 (April 2026))

• Maternity diagnoses (age 9 through 64): Age conflict edit. These diagnoses are clinically expected only in patients age 9 through 64.

Code annotations containing back-references to O12.12

Back-references to O12.1

• Type 1 Excludes: R80 Proteinuria ("gestational proteinuria (O12.1-)")

Back-references to O12

• Type 2 Excludes: O99.4 Diseases of the circulatory system complicating pregnancy, childbirth and the puerperium ("hypertensive disorders (O10-O16)")

Nearby codes

• O12.04 Gestational edema, complicating childbirth
• O12.05 Gestational edema, complicating the puerperium
• O12.1 Gestational proteinuria
• O12.10 Gestational proteinuria, unspecified trimester
• O12.11 Gestational proteinuria, first trimester
• O12.12 Gestational proteinuria, second trimester (this code)
• O12.13 Gestational proteinuria, third trimester
• O12.14 Gestational proteinuria, complicating childbirth
• O12.15 Gestational proteinuria, complicating the puerperium
• O12.2 Gestational edema with proteinuria
• O12.20 Gestational edema with proteinuria, unspecified trimester