O09.521 Supervision of elderly multigravida, first trimester

Billable ICD-10-CM code, FY2026. Exempt from present-on-admission (POA) reporting.

Applies from O09.5 Supervision of elderly primigravida and multigravida

Applicable to

• Pregnancy for a female 35 years and older at expected date of delivery

MS-DRG index

Defines the logic of DRG(s) 998 in MDC 14.

Approximate ICD-9-CM (GEMs)

• 659.61 Elderly multigravida, delivered with or without mention of antepartum condition (approximate)
• 659.63 Elderly multigravida, antepartum condition or complication (approximate)
• V23.82 Supervision of high-risk pregnancy with elderly multigravida (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.
• Unacceptable principal diagnosis: These codes describe a circumstance which influences care but is not a current illness or injury, or capture only an underlying condition, and are unacceptable as principal diagnosis.

Code annotations containing back-references to O09.521

Back-references to O09

• Type 1 Excludes: Z34 Encounter for supervision of normal pregnancy ("encounter for supervision of high risk pregnancy (O09.-)")
• Code First: Z3A Weeks of gestation ("obstetric condition or encounter for delivery (O09-O60, O80-O82, O94-O9A)")

Nearby codes

• O09.511 Supervision of elderly primigravida, first trimester
• O09.512 Supervision of elderly primigravida, second trimester
• O09.513 Supervision of elderly primigravida, third trimester
• O09.519 Supervision of elderly primigravida, unspecified trimester
• O09.52 Supervision of elderly multigravida
• O09.521 Supervision of elderly multigravida, first trimester (this code)
• O09.522 Supervision of elderly multigravida, second trimester
• O09.523 Supervision of elderly multigravida, third trimester
• O09.529 Supervision of elderly multigravida, unspecified trimester
• O09.6 Supervision of young primigravida and multigravida
• O09.61 Supervision of young primigravida