O99.312 Alcohol use complicating pregnancy, second trimester

Billable ICD-10-CM code, FY2026.

Applies from O99 Other maternal diseases classifiable elsewhere but complicating pregnancy, childbirth and the puerperium

Includes

• conditions which complicate the pregnant state, are aggravated by the pregnancy or are a main reason for obstetric care

Excludes2 (not included here)

• when the reason for maternal care is that the condition is known or suspected to have affected the fetus (O35-O36)

Use additional code

• code to identify specific condition

Applies from O99.31 Alcohol use complicating pregnancy, childbirth, and the puerperium

Use additional code

• code(s) from F10 to identify manifestations of the alcohol use

MS-DRG index

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

Approximate ICD-9-CM (GEMs)

• 648.41 Mental disorders of mother, delivered, with or without mention of antepartum condition (approximate)
• 648.43 Mental disorders of mother, 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.

Nearby codes

• O99.285 Endocrine, nutritional and metabolic diseases complicating the puerperium
• O99.3 Mental disorders and diseases of the nervous system complicating pregnancy, childbirth and the puerperium
• O99.31 Alcohol use complicating pregnancy, childbirth, and the puerperium
• O99.310 Alcohol use complicating pregnancy, unspecified trimester
• O99.311 Alcohol use complicating pregnancy, first trimester
• O99.312 Alcohol use complicating pregnancy, second trimester (this code)
• O99.313 Alcohol use complicating pregnancy, third trimester
• O99.314 Alcohol use complicating childbirth
• O99.315 Alcohol use complicating the puerperium
• O99.32 Drug use complicating pregnancy, childbirth, and the puerperium
• O99.320 Drug use complicating pregnancy, unspecified trimester