AutoICD API

R50.9

Billable

Fever, unspecified

Fever, unspecified

Status

Billable / Specific

Block

R50-R69

Parent Code

R50

ICD-11 Mapping

1 equivalent

Coding Notes

Inclusion Terms

Alternative clinical terms for this condition

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

Excludes 1

Codes that cannot be used together with this code (mutual exclusion)

Excludes 2

Conditions not included here, but the patient may have both

Related Codes(2)
R50.2

Drug induced fever

BillableR50.8

Other specified fever

ICD-11 Equivalents(1)

ICD-11 Equivalents

View full mapping

Corresponding ICD-11 codes from the WHO crosswalk mapping

MG26Fever of other or unknown originequivalentPrimary
Also Known As / Clinical Terms(348)

SNOMED CT

UMLS

Clinical Terms

  • Febrile syndrome
  • Artificial fever
  • Febrile leucopenia
  • fevers
  • fevers persistent
  • Intermittent fever
  • Hyperpyrexias
  • Fever of Unknown Origin
  • MH - malignant hyperpyrexia
  • Unknown Origin Fever
  • chills fever
  • Malignant hyperthermia
  • Recurrent pyrexia
  • Pyrexia NOS
  • Fever (finding)
  • Body temperature above reference range
  • Hyperpyrexia
  • Desquamation of skin following febrile illness
  • Prolonged fever
  • Recurrent fever
  • Neurogenic hyperthermia
  • Hyperthermia-hyperphagia-hypothyroidism syndrome
  • Myoclonus associated with fever
  • Swinging fever
  • chill fever
  • Pel-Ebstein fever
  • Exercise-induced malignant hyperthermia
  • Spiking fever
  • f.u.o.
  • Gradual fall of fever
  • Hyperthermia
  • Persistent fever
  • Sweating fever
  • Pyrexial
  • Rapid fall of fever
  • Lysis of fever
  • Chronic fever
  • Febrile myoclonus
  • Temperature elevated
  • temperature increase
  • Temperature elevation
  • Hyperpyrexia (finding)
  • Feels feverish
  • elevated temperature
  • Fever greater than 38 Celsius
  • fevers unknown origin
  • Temperature raised
  • Increased body temperature
  • Disorder characterised by fever
  • Febrile illness (fever)
  • Irregular fever
  • Fever, diurnal variation
  • Saddleback fever
  • fever with chills
  • High temperature
  • Pyrexia of unknown origin co-occurrent with human immunodeficiency virus infection
  • fever persistent
  • Viral fever
  • SFTS - Severe Fever with Thrombocytopenia Syndrome
  • Calor
  • Fever, persistent
  • Fever due to infection
  • Fever of unknown origin co-occurrent with human immunodeficiency virus infection
  • Chill
  • Finding of phase of fever
  • Feeling feverish
  • Has a temperature
  • Fast fall of fever
  • Fever defervescence
  • Slightly remittent fever
  • Fever NOS
  • feverish
  • fever chills
  • Reversed diurnal fever
  • fuo
  • Severe fever with thrombocytopenia syndrome
  • Malignant hyperthermia with arthrogryposis and torticollis syndrome
  • fever of unknown origin fuo
  • Fever with infection
  • febrile
  • Febrile illness
  • Hypothalamic fever
  • Fever with chills (finding)
  • Spiking temperature
  • Rising phase of fever
  • pyrexia of unknown origin
  • Mild pyrexia
  • Shivering
  • hyperthermic
  • f u o
  • febris
  • Periodic fever, not disease
  • Increased skin temperature
  • Staircase fever
  • chills with fever
  • Pyrexias
  • Picket fence fever
  • Chills and fever
  • Hyperpyrexial
  • Body temperature above reference range (finding)
  • Cough with fever
  • Disorder characterized by fever
  • pyrexia
  • Shivering or rigors
  • Feverish cold
  • chills fevers
  • Continuous fever
  • Plateau phase of fever
  • MHS - malignant hyperthermia susceptibility
  • fevered
  • Biphasic fever
  • Typhus inversus
  • Pyrexia of unknown origin (finding)
  • Hyperpyrexia NOS
  • Froster Iskenius Waterson syndrome
  • Sustained fever
  • Central fever
  • Swinging temperature
  • Endocrine hyperthermia
  • raised temperature
  • Falling phase of fever
  • Factitious fever
  • Unknown Origin Fevers
  • FTLS - Fever, thrombocytopenia, and leukopenia syndrome
  • Febrile leukopenia
  • Febrile disorder
  • Fever - rapid rise
  • Pel Ebstein fever
  • Phase of fever - finding
  • Fever caused by virus
  • Swinging pyrexia
  • fever of origin unknown
  • Low grade pyrexia
  • Aseptic fever
  • High body temperature
  • PUO - Pyrexia of unknown origin
  • Remittent fever
  • Fever with rigors
  • Body temperature increased
  • FTLS - Fever, thrombocytopenia, and leucopenia syndrome
  • Gradual rise of fever
  • Fever greater than 100.4 Fahrenheit
  • Dromedary fever
  • Fever of unknown origin [FUO]
  • increase temperature
  • increases temperature
  • Crisis of fever
  • Low grade fever
  • Acute rise of fever
  • fevers origin unknown
  • fever unknown origin
  • fever origin unknown
  • Fever - fast rise
Frequently Asked Questions
What is the ICD-10 code for fever, unspecified?

The ICD-10-CM code for fever, unspecified is R50.9. The full clinical description is "Fever, unspecified". R50.9 is a billable/specific code that can be used on insurance claims and medical billing.

What does ICD-10 code R50.9 mean?

ICD-10-CM code R50.9 represents “Fever, unspecified”. It is classified under Chapter 18: Symptoms, Signs and Abnormal Clinical and Laboratory Findings and is a billable/specific code that can be used on a claim.

Is R50.9 a billable code?

Yes, R50.9 is a billable/specific ICD-10-CM code and can be used to indicate a diagnosis on a medical claim.

What chapter is R50.9 in?

R50.9 is in Chapter 18: Symptoms, Signs and Abnormal Clinical and Laboratory Findings (codes R00-R99).

What codes cannot be used with R50.9?

R50.9 has Excludes1 notes indicating codes that cannot be used together with it, including: chills without fever (R68.83); febrile convulsions (R56.0-); fever of unknown origin during labor (O75.2); and 4 more.

What SNOMED CT codes does R50.9 map to?

R50.9 maps to 56 SNOMED CT concepts: 271749004, 111950007, 9619006, 248444008, 50177009, and 51 more. SNOMED CT is a clinical terminology used in electronic health records.

What are the UMLS CUIs for R50.9?

R50.9 is linked to 6 UMLS Concept Unique Identifiers: C0015967, C0085594, C0015970, C2830450, C0476474, and 1 more. The UMLS (Unified Medical Language System) integrates multiple biomedical vocabularies maintained by the U.S. National Library of Medicine.

How does R50.9 relate to ICF functioning codes?

ICF (International Classification of Functioning, Disability and Health) codes describe how conditions like fever, unspecified affect a person's functioning — body functions, activities, participation, and environmental factors. AutoICD provides ICF Core Sets for 12+ conditions and can map clinical text to ICF categories automatically. Browse the ICF directory to explore functioning codes.

What is the ICD-11 equivalent of R50.9?

R50.9 maps to the ICD-11 code: MG26 (Fever of other or unknown origin).

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Includes SNOMED Clinical Terms® (SNOMED CT®) used by permission of SNOMED International. Includes content from the UMLS Metathesaurus, courtesy of the U.S. National Library of Medicine.