ICD-10 O10.42
Billable / Specific MCCPre-existing secondary hypertension complicating childbirth
About ICD-10-CM O10.42
ICD-10-CM code O10.42 represents Pre-existing secondary hypertension complicating childbirth. This is a billable/specific code in the Pregnancy, Childbirth, and Puerperium chapter (block O10). The 2026 edition of ICD-10-CM O10.42 became effective on October 1, 2025.
Coding Tips for O10.42
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
O10.42 is designated MCC for MS-DRG grouping. On inpatient claims, this code can shift the DRG to the with-MCC variant when documented as a present-on-admission secondary diagnosis. Hospital CDI programs flag MCC 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, MCC
codes Pre-existing secondary hypertension complicating childbirth. As a Major Complication/Comorbidity (MCC), this can shift the DRG assignment to a higher-weighted category, substantial reimbursement impact.
Medicare LCD Coverage for O10.42
Local Coverage Determinations (LCDs) from CMS MACs that list O10.42 as a covered diagnosis.
Showing top 7. Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing O10.42.
1 Cigna
2 Medicare
CPT Codes Commonly Billed with O10.42
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 O10.42 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 |
|---|---|---|
| O10.42 | 64211 | 10000 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To O10.42
Other codes in section O10-O16 (Edema, proteinuria and hypertensive disorders in pregnancy, childbirth and the puerperium).
ICD-10 O10.42, Billing FAQ
Is ICD-10 code O10.42 billable? +
Yes, O10.42 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
Is O10.42 a CC or MCC for inpatient DRG? +
Yes, this code is designated as MCC. Documenting as a secondary diagnosis on inpatient claims can shift the DRG to a higher-weighted category.
What ICD-9 codes does O10.42 map to? +
Per CMS GEMs, O10.42 maps to ICD-9 codes: 64211. 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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