ICD-10 · PDGM grouping
O66 Other obstructed labor
All 10 codes in the O66 family, with the PDGM clinical group, comorbidity subgroup and primary-position rule CMS assigns, read from the CMS grouper crosswalk v07.2.26 and the CDC FY2027 code file.
Codes in family
10
Can lead a claim
0
Cannot lead a claim
10
What CMS assigns to O66
None of the 10 codes is assigned a clinical group. None of the 10 is assigned a comorbidity subgroup. None can lead a claim. CMS attaches a code-first note to 1 of the 10.
Code first
CMS grouper convention 146, on O66.41. Code first:
- rupture of uterus, if applicable (O71.0-, O71.1)
Every code in O66
Descriptions are CDC’s FY2027 wording; where CMS’s grouper abbreviates one, its form is shown beneath.
| Code | Description | Primary position | Clinical group | Comorbidity subgroup |
|---|---|---|---|---|
| O66.0 | Obstructed labor due to shoulder dystocia | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| O66.1 | Obstructed labor due to locked twins | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| O66.2 | Obstructed labor due to unusually large fetus | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| O66.3 | Obstructed labor due to other abnormalities of fetus | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| O66.4 Failed trial of labor | ||||
| O66.40 | Failed trial of labor, unspecified | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| O66.41 | Failed attempted vaginal birth after previous cesarean deliveryCMS: Failed attempt vaginal birth after previous cesarean del | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| O66.5 | Attempted application of vacuum extractor and forceps | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| O66.6 | Obstructed labor due to other multiple fetuses | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| O66.8 | Other specified obstructed labor | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| O66.9 | Obstructed labor, unspecified | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
Sources: CMS HH PPS Grouper Software v07.2.26, effective 2026-10-01, for the clinical group, comorbidity subgroup, code-first conventions and primary-position flags; CDC NCHS ICD-10-CM FY2027 code descriptions for the family title and code wording. This is the crosswalk Medicare runs a claim through. Grouping also depends on admission source, timing, the OASIS functional items and the rest of the diagnosis list.
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