O26.821 Pregnancy related peripheral neuritis, first trimester

Billable ICD-10-CM code, FY2026.

MS-DRG index

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

Approximate ICD-9-CM (GEMs)

• 646.41 Peripheral neuritis in pregnancy, delivered, with or without mention of antepartum condition (approximate)
• 646.42 Peripheral neuritis in pregnancy, delivered, with mention of postpartum complication (approximate)
• 646.43 Peripheral neuritis in pregnancy, 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 O26.821

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

• O26.811 Pregnancy related exhaustion and fatigue, first trimester
• O26.812 Pregnancy related exhaustion and fatigue, second trimester
• O26.813 Pregnancy related exhaustion and fatigue, third trimester
• O26.819 Pregnancy related exhaustion and fatigue, unspecified trimester
• O26.82 Pregnancy related peripheral neuritis
• O26.821 Pregnancy related peripheral neuritis, first trimester (this code)
• 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