O26.831 Pregnancy related renal disease, first trimester

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

Applies from O26.83 Pregnancy related renal disease

Use additional code

• code to identify the specific disorder

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)
• 646.22 Unspecified renal disease in pregnancy, without mention of hypertension, delivered, with mention of postpartum complication (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 O26.831

Back-references to O26.83

• Type 1 Excludes: R34 Anuria and oliguria ("anuria and oliguria complicating pregnancy (O26.83-)")

Back-references to O26.8

• Type 2 Excludes: O99.35 Diseases of the nervous system complicating pregnancy, childbirth, and the puerperium ("pregnancy related peripheral neuritis (O26.8-)")
• Type 1 Excludes: R53.8 Other malaise and fatigue ("exhaustion and fatigue due to pregnancy (O26.8-)")

Back-references to O26

• Type 1 Excludes: Z03.7 Encounter for suspected maternal and fetal conditions ruled out ("known or suspected fetal anomalies affecting management of mother, not ruled out (O26.-, O35.-, O36.-, O40.-, O41.-)")

Nearby codes

• O26.821 Pregnancy related peripheral neuritis, first trimester
• O26.822 Pregnancy related peripheral neuritis, second trimester
• O26.823 Pregnancy related peripheral neuritis, third trimester
• O26.829 Pregnancy related peripheral neuritis, unspecified trimester
• O26.83 Pregnancy related renal disease
• O26.831 Pregnancy related renal disease, first trimester (this code)
• O26.832 Pregnancy related renal disease, second trimester
• O26.833 Pregnancy related renal disease, third trimester
• O26.839 Pregnancy related renal disease, unspecified trimester
• O26.84 Uterine size-date discrepancy complicating pregnancy
• O26.841 Uterine size-date discrepancy, first trimester