ICD-10-CM Code For Unspecified Mycosis: Group Overview

The International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) code group B49 includes fungal infections where the specific fungal organism is not identified or documented, covering systemic and localized mycoses such as invasive or cutaneous fungal infections of unspecified etiology. These ICD-10-CM diagnosis codes are used to document clinical scenarios where the presence of a mycosis is confirmed but the causative organism or more specific classification is unavailable, capturing disease extent and clinical complexity. Accurate coding within the ICD-10-CM B49 group supports proper claim adjudication, complete clinical documentation, and appropriate reimbursement.

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ICD-10-CM B49: Unspecified Mycosis Overview

This group represents fungal infections that are not classified to a more specific organism or site, affecting skin, mucous membranes, or internal organs depending on clinical presentation. The codes target systemic and localized mycoses when the causal organism is unspecified or unspecified in documentation. Accurate coding affects clinical records and is important for correct claim processing and appropriate reimbursement.

When to Use

Use a code from this group when a mycosis is diagnosed but documentation lacks identification of the fungal species or more specific site-based code. These codes apply to clinical records and claims when treatment or diagnosis confirms a fungal infection without organism-level specificity.

ICD-10-CM Codes

1 rows

ICD-10-CM Code	Description
B49	Unspecified mycosis

DRG Codes

3 rows

DRG Code	Description
867	Other Infectious and Parasitic Diseases Diagnoses with MCC
868	Other Infectious and Parasitic Diseases Diagnoses with CC
869	Other Infectious and Parasitic Diseases Diagnoses without CC/MCC

Typical Clinical Scenarios

An adult patient presents to urgent care with several days of diffuse pruritic, scaly skin lesions after returning from travel; bedside KOH is inconclusive and the clinician documents a fungal infection without species identification pending laboratory results, so an unspecified mycosis diagnosis is assigned to capture the present fungal infection when organism-specific code is not available. Typical codes: B49.
An elderly patient in a long-term care facility has chronic, recurrent interdigital foot maceration and onychodystrophy; the primary team treats empirically but microbiology cultures are repeatedly non-diagnostic, and the chart lists a nonspecific fungal infection as a chronic comorbidity complicating skin integrity and care. Typical codes: B49.
A hospitalized immunocompromised patient (post-transplant) develops a systemic febrile illness with pulmonary infiltrates suspected to be fungal in origin, but bronchoalveolar lavage cultures and stains are pending or nonconfirmatory; clinicians document a mycosis of unspecified site while awaiting definitive identification, and the unspecified code is used for the active infectious process complicating the admission. Typical codes: B49.

Related Codes

B35-DERMATOPHYTOSIS

ICD-10-CM Code For Dermatophytosis: Group Overview

B36-OTHER-SUPERFICIAL-MYCOSES

ICD-10-CM Code For Other Superficial Mycoses: Group Overview

B37-CANDIDIASIS

ICD-10-CM Code For Candidiasis: Group Overview

B38-COCCIDIOIDOMYCOSIS

ICD-10-CM Code For Coccidioidomycosis: Group Overview

B39-HISTOPLASMOSIS

ICD-10-CM Code For Histoplasmosis: Group Overview

B41-PARACOCCIDIOIDOMYCOSIS

ICD-10-CM Code For Paracoccidioidomycosis: Group Overview

B42-SPOROTRICHOSIS-INFECTION

ICD-10-CM Code For Sporotrichosis: Group Overview

B43-CHROMOMYCOSIS-AND-PHEOMYCOTIC-ABSCESS

ICD-10-CM Code For Chromomycosis And Pheomycotic Abscess: Group Overview

B44-ASPERGILLOSIS

ICD-10-CM Code For Aspergillosis: Group Overview

B45-CRYPTOCOCCOSIS

ICD-10-CM Code For Cryptococcosis: Group Overview

Showing 1–10 of 13

Frequently Asked Questions

References

1.CPT® Codes and Descriptions. AAPC. Retrieved Aug 11, 2026.Maintains the CPT code set's official descriptions and guidelines, licensed from the American Medical Association, used as the definitional source for CPT codes on this page.
2.HCPCS Quarterly Update. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's quarterly release of HCPCS Level II codes and short/long descriptors, the source for HCPCS code definitions and update history.
3.ICD-10-CM Full Code List. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's complete ICD-10-CM diagnosis code list, used to cross-reference diagnosis codes associated with this procedure or service.

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When to Use

ICD-10-CM Codes

1 rows

ICD-10-CM Code	Description
B49	Unspecified mycosis

DRG Codes

3 rows

DRG Code	Description
867	Other Infectious and Parasitic Diseases Diagnoses with MCC
868	Other Infectious and Parasitic Diseases Diagnoses with CC
869	Other Infectious and Parasitic Diseases Diagnoses without CC/MCC

Typical Clinical Scenarios

An adult patient presents to urgent care with several days of diffuse pruritic, scaly skin lesions after returning from travel; bedside KOH is inconclusive and the clinician documents a fungal infection without species identification pending laboratory results, so an unspecified mycosis diagnosis is assigned to capture the present fungal infection when organism-specific code is not available. Typical codes: B49.
An elderly patient in a long-term care facility has chronic, recurrent interdigital foot maceration and onychodystrophy; the primary team treats empirically but microbiology cultures are repeatedly non-diagnostic, and the chart lists a nonspecific fungal infection as a chronic comorbidity complicating skin integrity and care. Typical codes: B49.
A hospitalized immunocompromised patient (post-transplant) develops a systemic febrile illness with pulmonary infiltrates suspected to be fungal in origin, but bronchoalveolar lavage cultures and stains are pending or nonconfirmatory; clinicians document a mycosis of unspecified site while awaiting definitive identification, and the unspecified code is used for the active infectious process complicating the admission. Typical codes: B49.

Related Codes

B35-DERMATOPHYTOSIS

ICD-10-CM Code For Dermatophytosis: Group Overview

B36-OTHER-SUPERFICIAL-MYCOSES

ICD-10-CM Code For Other Superficial Mycoses: Group Overview

B37-CANDIDIASIS

ICD-10-CM Code For Candidiasis: Group Overview

B38-COCCIDIOIDOMYCOSIS

ICD-10-CM Code For Coccidioidomycosis: Group Overview

B39-HISTOPLASMOSIS

ICD-10-CM Code For Histoplasmosis: Group Overview

B41-PARACOCCIDIOIDOMYCOSIS

ICD-10-CM Code For Paracoccidioidomycosis: Group Overview

B42-SPOROTRICHOSIS-INFECTION

ICD-10-CM Code For Sporotrichosis: Group Overview

B43-CHROMOMYCOSIS-AND-PHEOMYCOTIC-ABSCESS

ICD-10-CM Code For Chromomycosis And Pheomycotic Abscess: Group Overview

B44-ASPERGILLOSIS

ICD-10-CM Code For Aspergillosis: Group Overview

B45-CRYPTOCOCCOSIS

ICD-10-CM Code For Cryptococcosis: Group Overview

Showing 1–10 of 13

Frequently Asked Questions

References

1.CPT® Codes and Descriptions. AAPC. Retrieved Aug 11, 2026.Maintains the CPT code set's official descriptions and guidelines, licensed from the American Medical Association, used as the definitional source for CPT codes on this page.
2.HCPCS Quarterly Update. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's quarterly release of HCPCS Level II codes and short/long descriptors, the source for HCPCS code definitions and update history.
3.ICD-10-CM Full Code List. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's complete ICD-10-CM diagnosis code list, used to cross-reference diagnosis codes associated with this procedure or service.

Published by

Trek Health powers OpenPayer with a leading commercial payer intelligence platform, seamlessly converting fragmented payer data into actionable insights for provider organizations.

ICD-10-CM Code For Unspecified Mycosis: Group Overview

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ICD-10-CM B49: Unspecified Mycosis Overview

ICD-10-CM Code For Unspecified Mycosis: Group Overview

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ICD-10-CM B49: Unspecified Mycosis Overview

When to Use

ICD-10-CM Codes

DRG Codes

Typical Clinical Scenarios

Related Codes

When should a coder use `B49` for an ICD-10-CM diagnosis?

What clinical scenarios does the ICD-10-CM group `B49` cover?

How does accurate use of `B49` affect claims and records?

Which related DRGs may be assigned when `B49` is used as a diagnosis?

What documentation is implied as necessary when `B49` is reported?

References

When to Use

ICD-10-CM Codes

DRG Codes

Typical Clinical Scenarios

Related Codes

When should a coder use `B49` for an ICD-10-CM diagnosis?

What clinical scenarios does the ICD-10-CM group `B49` cover?

How does accurate use of `B49` affect claims and records?

Which related DRGs may be assigned when `B49` is used as a diagnosis?

What documentation is implied as necessary when `B49` is reported?

References