O43.101 Malformation of placenta, unspecified, first trimester

Billable ICD-10-CM code, FY2026.

Applies from O43 Placental disorders

Excludes2 (not included here)

• maternal care for poor fetal growth due to placental insufficiency (O36.5-)
• placenta previa (O44.-)
• placental polyp (O90.89)
• placentitis (O41.14-)
• premature separation of placenta [abruptio placentae] (O45.-)

Applies from O43.10 Malformation of placenta, unspecified

Applicable to

• Abnormal placenta NOS

MS-DRG index

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

Approximate ICD-9-CM (GEMs)

• 656.71 Other placental conditions, affecting management of mother, delivered, with or without mention of antepartum condition (approximate)
• 656.73 Other placental conditions, affecting management 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

• O43.022 Fetus-to-fetus placental transfusion syndrome, second trimester
• O43.023 Fetus-to-fetus placental transfusion syndrome, third trimester
• O43.029 Fetus-to-fetus placental transfusion syndrome, unspecified trimester
• O43.1 Malformation of placenta
• O43.10 Malformation of placenta, unspecified
• O43.101 Malformation of placenta, unspecified, first trimester (this code)
• O43.102 Malformation of placenta, unspecified, second trimester
• O43.103 Malformation of placenta, unspecified, third trimester
• O43.109 Malformation of placenta, unspecified, unspecified trimester
• O43.11 Circumvallate placenta
• O43.111 Circumvallate placenta, first trimester