O41.121Header code — not billable
Chorioamnionitis, first trimester
- Chapter
- 15. Pregnancy, childbirth and the puerperium
- Category
- O41
- Effective date
- October 1, 2026
Related codes in category O41
O41Other disorders of amniotic fluid and membranesO41.0OligohydramniosO41.00Oligohydramnios, unspecified trimesterO41.00X0Oligohydramnios, unsp trimester, not applicable or unspYesO41.00X1Oligohydramnios, unspecified trimester, fetus 1YesO41.00X2Oligohydramnios, unspecified trimester, fetus 2YesO41.00X3Oligohydramnios, unspecified trimester, fetus 3YesO41.00X4Oligohydramnios, unspecified trimester, fetus 4YesO41.00X5Oligohydramnios, unspecified trimester, fetus 5YesO41.00X9Oligohydramnios, unspecified trimester, other fetusYesO41.01Oligohydramnios, first trimesterO41.01X0Oligohydramnios, first trimester, not applicable or unspYes
Frequently asked questions
What is ICD-10 code O41.121?
O41.121 is an ICD-10-CM diagnosis code for Chorioamnionitis, first trimester.
Is O41.121 a billable code?
No. O41.121 is a category/header code, not billable on its own — use one of its more specific child codes instead.
What ICD-10-CM chapter is O41.121 in?
O41.121 falls under Chapter 15: Pregnancy, childbirth and the puerperium.
When did O41.121 become effective?
O41.121 has been effective since October 1, 2026, per the CMS/CDC ICD-10-CM annual release.
What other codes are related to O41.121?
O41.121 belongs to category O41, which includes 12 other codes — see the related codes list on this page.
ICD-10-CM data maintained by CDC/CMS (public domain). Always verify codes with authoritative sources before making coding or billing decisions.