2027 ICD-10-CM Diagnosis Code B49Unspecified mycosis
ICD-10-CM Codes›A00–B99›B35-B49›B49
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Not Chronic
B49 is a billable ICD-10-CM diagnosis code for unspecified mycosis. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 867 through 869. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 2 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Fungal infections.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Abscess of intracranial subdural space caused by fungus
- Abscess of spinal cord caused by fungus
- Abscess of subdural space caused by fungus
- Abscess of subdural space of spinal cord caused by fungus
- Acute fungal thyroiditis
- Acute fungal tubulointerstitial nephritis
- Acute infectious tubulointerstitial nephritis
- Acute pyelonephritis
- Acute sinusitis caused by fungus
- Acute thyroiditis
- Acute tubulointerstitial nephritis
- Allergic bronchopulmonary mycosis
- Allergic fungal sinusitis
- Arthropathy associated with a mycosis
- Arthropathy associated with mycoses, of the ankle and/or foot
- Arthropathy associated with mycoses, of the hand
- Arthropathy associated with mycoses, of the pelvic region and thigh
- Arthropathy associated with mycoses, of the shoulder region
- Bilateral fungal keratitis
- Bronchomoniliasis
- Candida sake or Candida famata or Yarrowia lipolytica
- Cardiovascular abnormality due to infective myocarditis
- Chorioamnionitis
- Chorioamnionitis caused by fungus
- Chronic catarrhal rhinitis
- Dilated cardiomyopathy due to fungal myocarditis
- Dilated cardiomyopathy due to infectious disease
- Duodenal ulcer caused by fungus
- Early neonatal infection caused by fungus
- Endogenous endophthalmitis
- Endogenous fungal endophthalmitis
- Enthesitis
- Erythema multiforme due to systemic fungal infection
- Erythema nodosum due to systemic fungal infection
- Exogenous fungal endophthalmitis
- Fungal arthritis
- Fungal cardiovascular infection
- Fungal chorioretinitis
- Fungal choroiditis
- Fungal colitis
- Fungal conjunctivitis
- Fungal duodenitis
- Fungal ear infection
- Fungal encephalitis
- Fungal endophthalmitis
- Fungal esophagitis
- Fungal gastroenteritis
- Fungal gastrointestinal infection
- Fungal granuloma
- Fungal hydrocephalus
- Fungal infection associated with peritoneal dialysis catheter
- Fungal infection of bile duct
- Fungal infection of brain
- Fungal infection of central nervous system
- Fungal infection of cerebrum
- Fungal infection of cranial nerve
- Fungal infection of eye
- Fungal infection of kidney
- Fungal infection of liver
- Fungal infection of lung
- Fungal keratitis
- Fungal meningitis
- Fungal musculoskeletal infection
- Fungal myocarditis
- Fungal myositis
- Fungal neuritis
- Fungal panuveitis
- Fungal peritonitis
- Fungal pneumonia
- Fungal respiratory infection
- Fungal sinusitis
- Fungal spinal cord compression
- Fungal spinal epidural abscess
- Fungal tenosynovitis
- Fungal ventriculitis
- Fungemia
- Fungus isolated but not further identified
- Gastric ulcer caused by fungus
- Gastritis caused by fungus
- Gingival erythema
- Granuloma of intracranial structure caused by fungus
- Granuloma of spinal cord caused by fungus
- Granuloma of spinal epidural space caused by fungus
- Infection associated with peritoneal dialysis catheter
- Infection caused by antimicrobial resistant fungi
- Infection causing granuloma of extradural space of spinal cord
- Infection causing granuloma of spinal cord
- Infection causing spondyloarthritis
- Infection of lacrimal gland caused by fungus
- Infection of peripheral nerve caused by fungus
- Infection of upper respiratory tract caused by fungus
- Infection of vagina caused by fungus
- Infectious panuveitis
- Infectious thyroiditis
- Infective ventriculitis
- Inflammation of bursa caused by fungus
- Inflammation of intervertebral disc caused by fungus
- Invasive fungal infection
- Invasive fungal sinusitis
- Keratitis of left eye caused by fungus
- Keratitis of right eye caused by fungus
- Linear gingival erythema
- Linear gingival erythema caused by fungus
- Mold isolated but not further identified
- Mycosis
- Mycosis due to human immunodeficiency virus infection
- Mycotic pericarditis
- Myelitis caused by fungus
- Neonatal fungal infection of skin
- Opportunistic infectious disease
- Opportunistic mycosis
- Opportunistic mycosis co-occurrent with human immunodeficiency virus infection
- Oral mucosal fungal disease
- Pichia kudriavzevii or Candida inconspicua
- Pichia kudriavzevii or Candida inconspicua or Candida lambica
- Pneumonia in systemic mycosis
- Recurrent infection caused by Fungi
- Rhinitis caseosa
- Sepsis caused by fungus
- Spinal epidural abscess
- Spinal subdural abscess
- Spinal subdural granuloma caused by fungus
- Spondyloarthritis caused by fungus
- Subdural abscess
- Subdural intracranial abscess
- Suppurative arthritis caused by fungus
- Systemic mycosis
- Thyroid infection
- Unidentified isolate
- Ventriculitis of the brain
- Yeast isolated but not further identified
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to B49: its own notes plus those printed at block B35-B49 and Chapter 1. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- diseases generally recognized as communicable or transmissible
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.
- Fungemia NOS
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.
- carrier or suspected carrier of infectious disease (Z22.-)
- certain localized infections - see body system-related chapters
- infectious and parasitic diseases complicating pregnancy, childbirth and the puerperium (O98.-)
- infectious and parasitic diseases specific to the perinatal period (P35-P39)
- influenza and other acute respiratory infections (J00-J22)
Use Additional Code
Add a second code, after this one, to fully describe the condition.
- code to identify resistance to antimicrobial drugs (Z16.-)
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name B49, its category, or a range that includes it.
Code First 1
These codes say to code first a condition named in the note, and B49 is one of the conditions named.
- J99 Respiratory disorders in diseases classified elsewherebronchomycosis (B49)
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Arthritis, arthritic (acute) (chronic) (nonpyogenic) (subacute) M19.90
mycosis NEC See Also: category M01; B49
mycotic NEC See Also: category M01; B49
Disease, diseased See Also: Syndrome;
fungus NEC B49
mycotic B49
Fungemia NOS B49
Infection, infected, infective (opportunistic) B99.9
fungus NOS B49
mycelium NOS B49
mycotic NOS B49
Keratomycosis B49
Meningitis (basal) (basic) (brain) (cerebral) (cervical) (congestive) (diffuse) (hemorrhagic) (infantile) (membranous) (metastatic) (nonspecific) (pontine) (progressive) (simple) (spinal) (subacute) (sympathetic) (toxic) G03.9
mycotic NEC B49
Mycosis, mycotic B49
Pneumomycosis B49
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Fungal Infections
If you have ever had athlete's foot or a yeast infection, you can blame a fungus. A fungus is a primitive organism. Mushrooms, mold and mildew are examples. Fungi live in air, in soil, on plants and in water. Some live in the human body. Only about half of all types of fungi are harmful.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert B49 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About B49Overview
What is the ICD-10 code for unspecified mycosis?
The ICD-10-CM code for unspecified mycosis is B49. It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is B49 (Unspecified mycosis) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report unspecified mycosis on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does B49 group to?
When unspecified mycosis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 867, 869, 868, with relative weights from 0.6784 to 2.1855 depending on complications. Higher weights mean higher Medicare reimbursement.
Is B49 a CC or MCC?
CMS lists B49 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 2 closely related codes in its exclusion list.
What is the ICD-9 equivalent of B49?
Under the General Equivalence Mappings, unspecified mycosis converts to ICD-9-CM 117.9 (mycoses NEC & NOS). The mapping is approximate, so confirm the match fits the documentation.
