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ICD-10-CM 2027

ICD-10 code for vivax malaria

B51.9

Plasmodium vivax malaria without complication

✓ Billable / specificCC — complication/comorbidity

From the official ICD-10-CM alphabetic index entry “Malaria, malarial (fever) › vivax”. Page updated September 29, 2026.

About coding vivax malaria

The ICD-10-CM code for vivax malaria is B51.9 (Plasmodium vivax malaria without complication). The official index lists 2 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on B51.9.

Within B51, choose B51.9 (without complication) only when documentation doesn't support a more specific option: with rupture of spleen (B51.0) and with other complications (B51.8).

As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.

In MS-DRG v44.0, it is part of the grouping logic for DRG 867 (Other Infectious and Parasitic Diseases Diagnoses with MCC, relative weight 2.1859), DRG 868 (Other Infectious and Parasitic Diseases Diagnoses with CC, relative weight 1.0235) and DRG 869 (Other Infectious and Parasitic Diseases Diagnoses without CC/MCC, relative weight 0.6787), in MDC 18 (Infectious and Parasitic Diseases, Systemic or Unspecified Sites), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

More specific vivax malaria codes (official index)

  • with
  • complications NEC B51.8 — Plasmodium vivax malaria with other complications
  • ruptured spleen B51.0 — Plasmodium vivax malaria with rupture of spleen

Common questions about vivax malaria ICD-10 codes

What is the ICD-10 code for vivax malaria?

B51.9 — Plasmodium vivax malaria without complication. More specific codes apply when the documentation supports them: B51.8, B51.0.

Is B51.9 billable?

Yes. B51.9 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can B51.9 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict B51.9 as a principal diagnosis.

Is B51.9 a CC or MCC?

B51.9 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.