ICD-10-CM Codes
R00-R99 Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
R50-R69 General symptoms and signs
R50- Fever of other and unknown origin
2022 ICD-10-CM Diagnosis Code R50.9

2022 ICD-10-CM Diagnosis Code R50.9

Fever, unspecified

2016

2017

2018

2019

2020

2021

2022

Billable/Specific Code

R50.9 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
The 2022 edition of ICD-10-CM R50.9 became effective on October 1, 2021.
This is the American ICD-10-CM version of R50.9 - other international versions of ICD-10 R50.9 may differ.

Applicable To

Fever NOS
Fever of unknown origin [FUO]
Fever with chills
Fever with rigors
Hyperpyrexia NOS
Persistent fever
Pyrexia NOS

The following code(s) above R50.9 contain annotation back-references

Annotation Back-References

In this context, annotation back-references refer to codes that contain:

Applicable To annotations, or
Code Also annotations, or
Code First annotations, or
Excludes1 annotations, or
Excludes2 annotations, or
Includes annotations, or
Note annotations, or
Use Additional annotations

that may be applicable to R50.9:

R00-R99
2022 ICD-10-CM Range R00-R99
Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
Note
- 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.
Type 2 Excludes
- abnormal findings on antenatal screening of mother (O28.-)
- certain conditions originating in the perinatal period (P04-P96)
- signs and symptoms classified in the body system chapters
- signs and symptoms of breast (N63, N64.5)
Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
R50
ICD-10-CM Diagnosis Code R50
Fever of other and unknown origin
Type 1 Excludes
- chills without fever (R68.83)
- febrile convulsions (R56.0-)
- fever of unknown origin during labor (O75.2)
- fever of unknown origin in newborn (P81.9)
- hypothermia due to illness (R68.0)
- malignant hyperthermia due to anesthesia (T88.3)
- puerperal pyrexia NOS (O86.4)
Fever of other and unknown origin

Approximate Synonyms

Febrile illness (fever)
Fever
Fever of unknown origin
Fever with chills
Pyrexia of unknown origin

Clinical Information

A disorder characterized by elevation of the body's temperature above the upper limit of normal.
A fever is a body temperature that is higher than normal. It is not an illness. It is part of your body's defense against infection. Most bacteria and viruses that cause infections do well at the body's normal temperature (98.6 f). A slight fever can make it harder for them to survive. Fever also activates your body's immune system.infections cause most fevers. There can be many other causes, including
- medicines
- heat exhaustion
- cancers
- autoimmune diseases
treatment depends on the cause of your fever. Your health care provider may recommend using over-the-counter medicines such as acetaminophen or ibuprofen to lower a very high fever. Adults can also take aspirin, but children with fevers should not take aspirin. It is also important to drink enough liquids to prevent dehydration.
A rise in body temperature above the normal, often as a response to infection. [goc:jl]
Abnormal elevation of body temperature, usually as a result of a pathologic process.
An abnormal elevation of body temperature, usually as a result of a pathologic process.
An increase in body temperature above normal (98.6 degrees f), usually caused by disease.
Fever in which the etiology cannot be ascertained.
Fever: a documented body temperature higher than 38 degrees c., or 100.4 degrees f.
The elevation of the body's temperature above the upper limit of normal, usually taken as 37.7 degrees c.

ICD-10-CM R50.9 is grouped within Diagnostic Related Group(s) (MS-DRG v39.0):

864 Fever and inflammatory conditions

Convert R50.9 to ICD-9-CM

Code History

2016 (effective 10/1/2015): New code (first year of non-draft ICD-10-CM)
2017 (effective 10/1/2016): No change
2018 (effective 10/1/2017): No change
2019 (effective 10/1/2018): No change
2020 (effective 10/1/2019): No change
2021 (effective 10/1/2020): No change
2022 (effective 10/1/2021): No change

Code annotations containing back-references to R50.9:

Type 1 Excludes: R68.83

ICD-10-CM Diagnosis Code R68.83
Chills (without fever)
Applicable To
- Chills NOS
Type 1 Excludes
- chills with fever (R50.9)

Diagnosis Index entries containing back-references to R50.9:

Chill(s) R68.83
ICD-10-CM Diagnosis Code R68.83
Chills (without fever)
Applicable To
Chills NOS
Type 1 Excludes
chills with fever (R50.9)
- with fever R50.9
Elevated, elevation
- body temperature R50.9 (of unknown origin)
Fever (inanition) (of unknown origin) (persistent) (with chills) (with rigor) R50.9
- intermittent (bilious) - see also Malaria
  - of unknown origin R50.9
- ephemeral R50.9 (of unknown origin)
- persistent R50.9 (of unknown origin)
- unknown origin R50.9
FUO R50.9 (fever of unknown origin)
High
- temperature R50.9 (of unknown origin)
Hyperpyrexia R50.9
- unknown origin R50.9
Inanition R64
ICD-10-CM Diagnosis Code R64
Cachexia
Applicable To
Wasting syndrome
Code First
underlying condition, if known
Type 1 Excludes
abnormal weight loss (R63.4)
nutritional marasmus (E41)
- fever R50.9
PUO R50.9 (pyrexia of unknown origin)
Pyrexia (of unknown origin) R50.9
- persistent R50.9
Rigors R68.89
ICD-10-CM Diagnosis Code R68.89
Other general symptoms and signs
- with fever R50.9
Temperature
- body, high R50.9 (of unknown origin)

ICD-10-CM Codes Adjacent To R50.9

R49.22 Hyponasality

R49.8 Other voice and resonance disorders

R49.9 Unspecified voice and resonance disorder

R50 Fever of other and unknown origin

R50.2 Drug induced fever

R50.8 Other specified fever

R50.81 Fever presenting with conditions classified elsewhere

R50.82 Postprocedural fever

R50.83 Postvaccination fever

R50.84 Febrile nonhemolytic transfusion reaction

R50.9 Fever, unspecified

R51 Headache

R51.0 Headache with orthostatic component, not elsewhere classified

R51.9 Headache, unspecified

R52 Pain, unspecified

R53 Malaise and fatigue

R53.0 Neoplastic (malignant) related fatigue

R53.1 Weakness

R53.2 Functional quadriplegia

R53.8 Other malaise and fatigue

R53.81 Other malaise

Reimbursement claims with a date of service on or after October 1, 2015 require the use of ICD-10-CM codes.

2022 ICD-10-CM Diagnosis Code R50.9

Fever, unspecified

Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified

Fever of other and unknown origin

Chills (without fever)

Chills (without fever)

Cachexia

Other general symptoms and signs