ICD-10 O11.9
Billable / SpecificPre-existing hypertension with pre-eclampsia, unspecified trimester
About ICD-10-CM O11.9
ICD-10-CM code O11.9 represents Pre-existing hypertension with pre-eclampsia, unspecified trimester. This is a billable/specific code in the Pregnancy, Childbirth, and Puerperium chapter (block O11). The 2026 edition of ICD-10-CM O11.9 became effective on October 1, 2025.
Coding Tips for O11.9
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.
Medicare LCD Coverage for O11.9
Local Coverage Determinations (LCDs) from CMS MACs that list O11.9 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 O11.9.
1 Aetna
1 Cigna
CPT Codes Commonly Billed with O11.9
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.
Convert O11.9 to ICD-9-CM
Per CMS General Equivalence Mappings (GEMs), useful for legacy data review and historical claim analysis.
| ICD-10 | ICD-9 | Mapping Flags |
|---|---|---|
| O11.9 | 64220 | 10000 |
| O11.9 | 64270 | 10000 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To O11.9
Other codes in section O10-O16 (Edema, proteinuria and hypertensive disorders in pregnancy, childbirth and the puerperium).
ICD-10 O11.9, Billing FAQ
Is ICD-10 code O11.9 billable? +
Yes, O11.9 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
What ICD-9 codes does O11.9 map to? +
Per CMS GEMs, O11.9 maps to ICD-9 codes: 64220, 64270. Useful for legacy data review and historical claim analysis.
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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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