O66.4Header code — not billable
Failed trial of labor
- Chapter
- 15. Pregnancy, childbirth and the puerperium
- Category
- O66
- Effective date
- October 1, 2026
Related codes in category O66
O66Other obstructed laborO66.0Obstructed labor due to shoulder dystociaYesO66.1Obstructed labor due to locked twinsYesO66.2Obstructed labor due to unusually large fetusYesO66.3Obstructed labor due to other abnormalities of fetusYesO66.40Failed trial of labor, unspecifiedYesO66.41Failed attempt vaginal birth after previous cesarean delYesO66.5Attempted application of vacuum extractor and forcepsYesO66.6Obstructed labor due to other multiple fetusesYesO66.8Other specified obstructed laborYesO66.9Obstructed labor, unspecifiedYes
Frequently asked questions
What is ICD-10 code O66.4?
O66.4 is an ICD-10-CM diagnosis code for Failed trial of labor.
Is O66.4 a billable code?
No. O66.4 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 O66.4 in?
O66.4 falls under Chapter 15: Pregnancy, childbirth and the puerperium.
When did O66.4 become effective?
O66.4 has been effective since October 1, 2026, per the CMS/CDC ICD-10-CM annual release.
What other codes are related to O66.4?
O66.4 belongs to category O66, which includes 11 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.