Is ICD-10-CM code B45 billable?

No, B45 (Cryptococcosis) is a non-billable ICD-10-CM code. It must be coded to a more specific subcategory before it can be used for reimbursement.

What chapter does ICD-10-CM code B45 belong to?

B45 belongs to Chapter 1 of the ICD-10-CM tabular list: A00–B99 (Certain Infectious and Parasitic Diseases).

B45Not billable, use a more specific code below

Cryptococcosis

In Mycoses (B35-B49), chapter 1: Certain Infectious and Parasitic Diseases

7 billable codes under B45: 1 is an MCC, 6 are a CC; all map to HCC 6 (Opportunistic Infections).A CC or MCC (major CC) is a secondary diagnosis that raises the MS-DRG payment. An HCC counts toward a Medicare Advantage patient's risk score.

Instructional notes

Also applies, from Mycoses (B35-B49)

These notes sit on B35-B49 and apply to every code under it, including B45.

Excludes2: not included here, code separately if applicable

hypersensitivity pneumonitis due to organic dust (J67.-)
mycosis fungoides (C84.0-)

Official coding guidelines

From the ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027 (CMS and NCHS). Links open the PDF at the right page.

Rules for coding infections and parasitic diseases, including HIV, organism and drug resistance codes, sepsis and septic shock, MRSA, Zika, and COVID-19.

Human Immunodeficiency Virus (HIV) Infections (page 19)
Infectious agents as the cause of diseases classified to other chapters (page 22)
Infections resistant to antibiotics (page 22)
Sepsis, Severe Sepsis, and Septic Shock (page 23)
Methicillin Resistant Staphylococcus aureus (MRSA) Conditions (page 27)
Zika virus infections (page 28)
Coronavirus infections (page 28)

Read Section I.C.1 (page 19)

All codes under B45

B45 can't be used on a claim. Pick a billable code below; grey headings group them.

B45 MS-DRGs

As the principal diagnosis, the billable codes under B45 group to these 13 MS-DRGs (v44.0). Which one applies depends on procedures performed, secondary diagnoses (CC/MCC), and the patient's age and discharge status.

DRG 791 Prematurity with Major Problems (7 of 7 codes)
DRG 793 Full Term Neonate with Major Problems (7 of 7 codes)
DRG 867 Other Infectious and Parasitic Diseases Diagnoses with MCC (6 of 7 codes)
DRG 868 Other Infectious and Parasitic Diseases Diagnoses with CC (6 of 7 codes)
DRG 869 Other Infectious and Parasitic Diseases Diagnoses without CC/MCC (6 of 7 codes)
DRG 974 HIV with Major Related Condition with MCC (6 of 7 codes)
DRG 975 HIV with Major Related Condition with CC (6 of 7 codes)
DRG 976 HIV with Major Related Condition without CC/MCC (6 of 7 codes)
DRG 023 Craniotomy with Major Device Implant or Acute Complex CNS Principal Diagnosis with MCC or Antineoplastic Implant or Epilepsy with Neurostimulator (1 of 7 codes)
DRG 024 Craniotomy with Major Device Implant or Acute Complex CNS Principal Diagnosis without MCC (1 of 7 codes)
DRG 097 Non-Bacterial Infection of Nervous System Except Viral Meningitis with MCC (1 of 7 codes)
DRG 098 Non-Bacterial Infection of Nervous System Except Viral Meningitis with CC (1 of 7 codes)
DRG 099 Non-Bacterial Infection of Nervous System Except Viral Meningitis without CC/MCC (1 of 7 codes)

About the condition

Plain-language background from MedlinePlus (National Library of Medicine), not coding guidance.

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.

Code history

Valid since FY2016, when ICD-10-CM took effect on October 1, 2015. No changes since.