2027 ICD-10-CM Diagnosis Code R50.83Postvaccination fever
ICD-10-CM Codes›R00–R99›R50-R69›R50
- Billable — Valid for Submission
- Not Chronic
R50.83 is a billable ICD-10-CM diagnosis code for postvaccination fever. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 864. As a symptom code, it should not be used as a principal diagnosis once a related definitive diagnosis has been established. Coders also document this condition as adverse reaction to pertussis vaccine. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Fever.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Adverse reaction to pertussis vaccine
- Fever caused by diphtheria vaccine
- Fever caused by pertussis vaccine
- Fever caused by tetanus vaccine
- Fever caused by vaccine
- Fever caused by vaccine product containing only Bordetella pertussis and Clostridium tetani and Corynebacterium diphtheriae antigens
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to R50.83: its own notes plus those printed at R50 and Chapter 18. A note printed at a category, block or chapter applies to every code under it.
Applicable To
Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.
- Postimmunization fever
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
Notes
General instructions on how these codes are used.
- This chapter includes symptoms, signs, abnormal results of clinical or other investigative procedures, and ill-defined conditions regarding which no diagnosis classifiable elsewhere is recorded.
- Signs and symptoms that point rather definitely to a given diagnosis have been assigned to a category in other chapters of the classification. In general, categories in this chapter include the less well-defined conditions and symptoms that, without the necessary study of the case to establish a final diagnosis, point perhaps equally to two or more diseases or to two or more systems of the body. Practically all categories in the chapter could be designated 'not otherwise specified', 'unknown etiology' or 'transient'. The Alphabetical Index should be consulted to determine which symptoms and signs are to be allocated here and which to other chapters. The residual subcategories, numbered .8, are generally provided for other relevant symptoms that cannot be allocated elsewhere in the classification.
- The conditions and signs or symptoms included in categories R00-R94 consist of:
- (a) cases for which no more specific diagnosis can be made even after all the facts bearing on the case have been investigated;
- (b) signs or symptoms existing at the time of initial encounter that proved to be transient and whose causes could not be determined;
- (c) provisional diagnosis in a patient who failed to return for further investigation or care;
- (d) cases referred elsewhere for investigation or treatment before the diagnosis was made;
- (e) cases in which a more precise diagnosis was not available for any other reason;
- (f) certain symptoms, for which supplementary information is provided, that represent important problems in medical care in their own right.
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name R50.83, its category, or a range that includes it.
Excludes1 2
These codes carry an Excludes1 note naming R50.83: they are not reported together with it, unless the two conditions are unrelated.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Fever
A fever is a body temperature that is higher than normal. A normal temperature can vary from person to person, but it is usually around 98.6 °F (37 °C). A fever is not a disease. It is usually a sign that your body is trying to fight an illness or infection.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert R50.83 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About R50.83Overview
What is the ICD-10 code for postvaccination fever?
The ICD-10-CM code for postvaccination fever is R50.83 (sometimes written as R5083). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is R50.83 (Other specified fever) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report postvaccination fever on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does R50.83 group to?
When postvaccination fever is the principal diagnosis on an inpatient stay, it groups to MS-DRG 864 (fever and Inflammatory Conditions), which carries a relative weight of 0.8553. Higher weights mean higher Medicare reimbursement.
Can R50.83 be a principal diagnosis?
Use it with care. This is a symptom code, so once a definitive diagnosis explaining the postvaccination fever is established, that condition takes the principal position instead.
Can R50.83 be reported with R68.83?
Not as a rule. The Excludes1 note at R50, which applies to R50.83, lists "chills without fever (R68.83)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
