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O35.10

O35.10Maternal care for (suspected) chromosomal abnormality in fetus, unspecified

Non-billable headerICD-10-CM

O35.10 is a non-billable header ICD-10-CM code for maternal care for (suspected) chromosomal abnormality in fetus, unspecified. It cannot be billed on its own: choose one of the more specific child codes below. This code also requires a 7th character before it is complete.

This code requires a 7th character

One of the following 7th characters is to be assigned to each code under category O35. 7th character 0 is for single gestations and multiple gestations where the fetus is unspecified. 7th characters 1 through 9 are for cases of multiple gestations to identify the fetus for which the code applies. The appropriate code from category O30, Multiple gestation, must also be assigned when assigning a code from category O35 that has a 7th character of 1 through 9.

0
not applicable or unspecified
1
fetus 1
2
fetus 2
3
fetus 3
4
fetus 4
5
fetus 5
9
other fetus

Risk adjustment

O35.10 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

How O35.10 is indexed

Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to O35.10.

  • Pregnancycomplicated byfetalchromosomal abnormality(conditions in Q90-Q99)

Code to one of these instead O35.10

7 child codes. Green means billable.

Related codes at this level

Codes that share O35.1. If O35.10 is not quite right, the correct code is usually one of these.

Questions about O35.10

Is O35.10 a billable ICD-10-CM code?
No. O35.10 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does O35.10 sit in the tabular list?
Pregnancy, childbirth and the puerperium (O00-O9A), in the block Maternal care related to the fetus and amniotic cavity and possible delivery problems (O30-O48).
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.