Is O35.09X9 a billable ICD-10-CM code?

Yes. O35.09X9 is a billable, specific ICD-10-CM code and is valid for submission on a claim.

Where does O35.09X9 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).

What cannot be coded together with O35.09X9?

O35.09X9 carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above O35.09X9 (O35) and apply to it just the same.

O35.09X9

O35.09X9 — Maternal care for (suspected) other central nervous system malformation or damage in fetus, other fetus

Billable / specific codeICD-10-CM

O35.09X9 is a billable, specific ICD-10-CM code for maternal care for (suspected) other central nervous system malformation or damage in fetus, other fetus. It is valid for submission on a claim.

7th character "9" — other fetus

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

Excludes1 inherited from the categories above O35.09X9

These are not written on O35.09X9, but they bind it: a note on a category applies to every code beneath it. Billing O35.09X9 with anything listed here is a denial.

Written on O35 — Maternal care for known or suspected fetal abnormality and damage

encounter for suspected maternal and fetal conditions ruled out (Z03.7-)

Excludes2 inherited from the categories above O35.09X9

Also inherited, and the opposite of Excludes1: these conditions are not part of O35.09X9, but a patient can have both, so you may code both.

Written on O35.0 — Maternal care for (suspected) central nervous system malformation in fetus

chromosomal abnormality in fetus (O35.1-)

Other codes that can never be billed with O35.09X9

These codes carry an Excludes1 note pointing at O35.09X9. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading O35.09X9 alone.

Z03.7Encounter for suspected maternal and fetal conditions ruled out

Risk adjustment

O35.09X9 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.

Medicare coverage

O35.09X9 is named in 1 Medicare coverage policy — 1 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

A55326Billing and Coding: Zika Virus Testing by PCR and ELISA Methods

Code history

O35.09X9 has not changed since FY2024 — no addition, revision or deletion across the three most recent ICD-10-CM releases.

Related codes at this level

Codes that share O35.09. If O35.09X9 is not quite right, the correct code is usually one of these.

Questions about O35.09X9

Is O35.09X9 a billable ICD-10-CM code?: Yes. O35.09X9 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does O35.09X9 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).
What cannot be coded together with O35.09X9?: O35.09X9 carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above O35.09X9 (O35) and apply to it just the same.