O99.333 Smoking (tobacco) complicating pregnancy, third 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 O99.33 Tobacco use disorder complicating pregnancy, childbirth, and the puerperium

Applicable to

• Smoking complicating pregnancy, childbirth, and the puerperium

Use additional code

• code from category F17 to identify type of tobacco nicotine dependence

MS-DRG index

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

Approximate ICD-9-CM (GEMs)

• 649.01 Tobacco use disorder complicating pregnancy, childbirth, or the puerperium, delivered, with or without mention of antepartum condition (approximate)
• 649.03 Tobacco use disorder complicating pregnancy, childbirth, or the puerperium, 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 O99.333

Back-references to O99.33

• Type 2 Excludes: F17 Nicotine dependence ("tobacco use (smoking) during pregnancy, childbirth and the puerperium (O99.33-)")
• Type 1 Excludes: Z72.0 Tobacco use ("tobacco use during pregnancy (O99.33-)")

Nearby codes

• O99.325 Drug use complicating the puerperium
• O99.33 Tobacco use disorder complicating pregnancy, childbirth, and the puerperium
• O99.330 Smoking (tobacco) complicating pregnancy, unspecified trimester
• O99.331 Smoking (tobacco) complicating pregnancy, first trimester
• O99.332 Smoking (tobacco) complicating pregnancy, second trimester
• O99.333 Smoking (tobacco) complicating pregnancy, third trimester (this code)
• O99.334 Smoking (tobacco) complicating childbirth
• O99.335 Smoking (tobacco) complicating the puerperium
• O99.34 Other mental disorders complicating pregnancy, childbirth, and the puerperium
• O99.340 Other mental disorders complicating pregnancy, unspecified trimester
• O99.341 Other mental disorders complicating pregnancy, first trimester