ICD-10 O10.912
Billable / Specific CCUnspecified pre-existing hypertension complicating pregnancy, second trimester
About ICD-10-CM O10.912
ICD-10-CM code O10.912 represents Unspecified pre-existing hypertension complicating pregnancy, second trimester. This is a billable/specific code in the Pregnancy, Childbirth, and Puerperium chapter (block O10). The 2026 edition of ICD-10-CM O10.912 became effective on October 1, 2025.
Coding Tips for O10.912
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
O10.912 is designated CC for MS-DRG grouping. On inpatient claims, this code can shift the DRG to the with-CC variant when documented as a present-on-admission secondary diagnosis. Hospital CDI programs flag CC opportunities during chart review. Failure to capture this code may leave 30 to 80 percent of the inpatient stay revenue unrealized.
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.
Inpatient DRG Impact, CC
codes Unspecified pre-existing hypertension complicating pregnancy, second trimester. As a Complication/Comorbidity (CC), this contributes to DRG severity adjustment when documented alongside the principal diagnosis.
Medicare LCD Coverage for O10.912
Local Coverage Determinations (LCDs) from CMS MACs that list O10.912 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 O10.912.
Our payer policy database covers Aetna, Cigna, Anthem, BCBS, Humana, and Medicare Advantage plans, but O10.912 doesn't currently appear in any indexed policy. The code may still be covered under standard plan benefits.
CPT Codes Commonly Billed with O10.912
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 O10.912 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 |
|---|---|---|
| O10.912 | 64201 | 10000 |
| O10.912 | 64203 | 10000 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To O10.912
Other codes in section O10-O16 (Edema, proteinuria and hypertensive disorders in pregnancy, childbirth and the puerperium).
ICD-10 O10.912, Billing FAQ
Is ICD-10 code O10.912 billable? +
Yes, O10.912 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
Is O10.912 a CC or MCC for inpatient DRG? +
Yes, this code is designated as CC. Documenting as a secondary diagnosis on inpatient claims can shift the DRG to a higher-weighted category.
What ICD-9 codes does O10.912 map to? +
Per CMS GEMs, O10.912 maps to ICD-9 codes: 64201, 64203. 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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