ICD-10 O35
Non-Billable HeaderMaternal care for known or suspected fetal abnormality and damage
About ICD-10-CM O35
ICD-10-CM code O35 represents Maternal care for known or suspected fetal abnormality and damage. This is a non-billable header code in the Pregnancy, Childbirth, and Puerperium chapter (block O35). The 2026 edition of ICD-10-CM O35 became effective on October 1, 2025. Non-billable codes cannot be used as a primary or secondary diagnosis on a claim, use a more specific child code instead.
Coding Tips for O35
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
Most O codes require a 7th character indicating trimester (1 = first, 2 = second, 3 = third). Some require fetus identification character. Code O09 (supervision of high-risk pregnancy) is required as a secondary code when applicable.
Type 1 Excludes
Pure excludes, these codes can never be coded together with O35. The conditions are mutually exclusive (e.g., congenital vs acquired forms).
- encounter for suspected maternal and fetal conditions ruled out (Z03.7-)
Includes
- the listed conditions in the fetus as a reason for hospitalization or other obstetric care to the mother, or for termination of pregnancy
Coding Notes
Code Also
- any associated maternal condition
Seven Chr Note
- 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.
Medicare LCD Coverage for O35
Local Coverage Determinations (LCDs) from CMS MACs that list O35 as a covered diagnosis.
This doesn't mean the code isn't covered, it means no MAC has issued a Local Coverage Determination naming this specific code. Coverage may still apply under National Coverage Determinations or general medical-necessity rules.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing O35.
Our payer policy database covers Aetna, Cigna, Anthem, BCBS, Humana, and Medicare Advantage plans, but O35 doesn't currently appear in any indexed policy. The code may still be covered under standard plan benefits.
CPT Codes Commonly Billed with O35
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
We don't have CPT pairings indexed for this specific code yet. Use the CPT search above to find common procedures, or check your payer's published medical policy for code-specific guidance.
Codes Adjacent To O35
Other codes in section O30-O48 (Maternal care related to the fetus and amniotic cavity and possible delivery problems).
ICD-10 O35, Billing FAQ
Is ICD-10 code O35 billable? +
No, O35 is a non-billable header code. Use a more specific child code from block O35 when submitting claims.
What codes are Type 1 Excludes for O35? +
Type 1 Excludes (never code together with O35): encounter for suspected maternal and fetal conditions ruled out (Z03.7-)
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Reviewed by the PayerReady Medical Coding Team
Verified against the CMS 2026 code set on May 31, 2026.
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