ICD-10-CM 2027 diagnosis code

B51Plasmodium vivax malaria

Not billable — use a more specific code

B51 is a header code, so it can't be reported by itself. Choose one of the 3 more specific codes beneath it.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About B51

B51 is the ICD-10-CM diagnosis code for Plasmodium vivax malaria. It belongs to block B50-B64 (protozoal diseases) and chapter 1 (certain infectious and parasitic diseases). It is a header code, so it can't be reported by itself; one of its 3 subcodes must be used instead.

To report this condition, pick the subcode that matches the documentation: B51.0 (with rupture of spleen), B51.8 (with other complications) and B51.9 (without complication).

Don't report B51 together with the conditions in its Excludes1 note: plasmodium vivax with Plasmodium falciparum (B50.-).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Specific codes under B51

Coding notes

IncludesFurther defines the content of the category

mixed infections of Plasmodium vivax with other Plasmodium species, except Plasmodium falciparum

Excludes1Not coded here — never report together with this code

plasmodium vivax with Plasmodium falciparum (B50.-)

Notes that apply from higher levels

Instructions written at a parent level also apply to B51.

Broader instructions also apply from B50-B64 Protozoal diseases and Chapter 1: Certain infectious and parasitic diseases.

Codes whose notes reference B51

B52Excludes1
B53.0Excludes1
B53.1Excludes1

Code history

2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027

FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
No changes since FY2016.

Common questions about B51

Is B51 billable?: No. B51 is a header code. Report one of its more specific subcodes instead.