O99.820 Streptococcus B carrier state complicating pregnancy

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 O99.8 Other specified diseases and conditions complicating pregnancy, childbirth and the puerperium

Applicable to

• Conditions in D00-D48, H00-H95, M00-N99, and Q00-Q99

Excludes2 (not included here)

• genitourinary infections in pregnancy (O23.-)
• infection of genitourinary tract following delivery (O86.1-O86.4)
• malignant neoplasm complicating pregnancy, childbirth and the puerperium (O9A.1-)
• maternal care for known or suspected abnormality of maternal pelvic organs (O34.-)
• postpartum acute kidney failure (O90.49)
• traumatic injuries in pregnancy (O9A.2-)

Use additional code

• code to identify condition

Applies from O99.82 Streptococcus B carrier state complicating pregnancy, childbirth and the puerperium

Excludes1 (never code together)

• Carrier of streptococcus group B (GBS) in a nonpregnant woman (Z22.330)

MS-DRG index

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

Approximate ICD-9-CM (GEMs)

• 648.93 Other current conditions classifiable elsewhere of mother, antepartum condition or complication (approximate)
• V02.51 Carrier or suspected carrier of group B streptococcus (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 O99.820

Back-references to O99.82

• Type 2 Excludes: O98 Maternal infectious and parasitic diseases classifiable elsewhere but complicating pregnancy, childbirth and the puerperium ("infectious carrier state (O99.82-, O99.83-)")
• Type 1 Excludes: Z22.330 Carrier of Group B streptococcus ("Carrier of streptococcus group B (GBS) complicating pregnancy, childbirth and the puerperium (O99.82-)")

Diagnosis Index entries for O99.820

• Pregnancy (single) (uterine) › complicated by (care of) (management affected by) › infection (s) › carrier state NEC › streptococcus B
• Pregnancy (single) (uterine) › complicated by (care of) (management affected by) › streptococcus group B (GBS) carrier state

Nearby codes

• O99.81 Abnormal glucose complicating pregnancy, childbirth and the puerperium
• O99.810 Abnormal glucose complicating pregnancy
• O99.814 Abnormal glucose complicating childbirth
• O99.815 Abnormal glucose complicating the puerperium
• O99.82 Streptococcus B carrier state complicating pregnancy, childbirth and the puerperium
• O99.820 Streptococcus B carrier state complicating pregnancy (this code)
• O99.824 Streptococcus B carrier state complicating childbirth
• O99.825 Streptococcus B carrier state complicating the puerperium
• O99.83 Other infection carrier state complicating pregnancy, childbirth and the puerperium
• O99.830 Other infection carrier state complicating pregnancy
• O99.834 Other infection carrier state complicating childbirth