O30.012 Twin pregnancy, monochorionic/monoamniotic, second trimester

Billable ICD-10-CM code, FY2026.

Applies from O30 Multiple gestation

Code also

• any complications specific to multiple gestation

Applies from O30.01 Twin pregnancy, monochorionic/monoamniotic

Applicable to

• Twin pregnancy, one placenta, one amniotic sac

Excludes1 (never code together)

• conjoined twins (O30.02-)

MS-DRG index

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

Approximate ICD-9-CM (GEMs)

• 651.01 Twin pregnancy, delivered, with or without mention of antepartum condition (approximate)
• 651.03 Twin pregnancy, antepartum condition or complication (approximate)
• V91.01 Twin gestation, monochorionic/monoamniotic (one placenta, one amniotic sac) (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

• O30.002 Twin pregnancy, unspecified number of placenta and unspecified number of amniotic sacs, second trimester
• O30.003 Twin pregnancy, unspecified number of placenta and unspecified number of amniotic sacs, third trimester
• O30.009 Twin pregnancy, unspecified number of placenta and unspecified number of amniotic sacs, unspecified trimester
• O30.01 Twin pregnancy, monochorionic/monoamniotic
• O30.011 Twin pregnancy, monochorionic/monoamniotic, first trimester
• O30.012 Twin pregnancy, monochorionic/monoamniotic, second trimester (this code)
• O30.013 Twin pregnancy, monochorionic/monoamniotic, third trimester
• O30.019 Twin pregnancy, monochorionic/monoamniotic, unspecified trimester
• O30.02 Conjoined twin pregnancy
• O30.021 Conjoined twin pregnancy, first trimester
• O30.022 Conjoined twin pregnancy, second trimester