Is ICD-10-CM code B44 billable?

No, B44 (Aspergillosis) 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 B44 belong to?

B44 belongs to Chapter 1 of the ICD-10-CM tabular list: A00–B99 (Certain Infectious and Parasitic Diseases).

B44Not billable, use a more specific code below

Aspergillosis

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

7 billable codes under B44: 1 is an MCC, 6 are a CC; all map to HCC 6 (Opportunistic Infections), HCC 280 (Chronic Obstructive Pulmonary Disease, Interstitial Lung Disorders, and Other Chronic Lung Disorders).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

Code also: add a code for this too, order depends on the encounter

if applicable:
aspergilloma of other site - code to chronic infection of site
pulmonary aspergilloma (J4B)
pulmonary aspergillosis fungal ball (J4B)
pulmonary mycetoma (J4B)
sinus aspergilloma (J32.-)

Also applies, from Mycoses (B35-B49)

These notes sit on B35-B49 and apply to every code under it, including B44.

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 B44

B44 can't be used on a claim. Pick a billable code below; grey headings group them.

B44 MS-DRGs

As the principal diagnosis, the billable codes under B44 group to these 11 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 (5 of 7 codes)
DRG 793 Full Term Neonate with Major Problems (5 of 7 codes)
DRG 867 Other Infectious and Parasitic Diseases Diagnoses with MCC (5 of 7 codes)
DRG 868 Other Infectious and Parasitic Diseases Diagnoses with CC (5 of 7 codes)
DRG 869 Other Infectious and Parasitic Diseases Diagnoses without CC/MCC (5 of 7 codes)
DRG 177 Respiratory Infections and Inflammations with MCC (1 of 7 codes)
DRG 178 Respiratory Infections and Inflammations with CC (1 of 7 codes)
DRG 179 Respiratory Infections and Inflammations without CC/MCC (1 of 7 codes)
DRG 196 Interstitial Lung Disease with MCC (1 of 7 codes)
DRG 197 Interstitial Lung Disease with CC (1 of 7 codes)
DRG 198 Interstitial Lung Disease without CC/MCC (1 of 7 codes)

Other codes that refer to B44

Notes on these codes point to B44.

J4B Code Also: aspergillosis (B44.-)
J82 Excludes2: pulmonary eosinophilia due to aspergillosis (B44.-)

About the condition

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

Aspergillosis

Aspergillosis is a disease caused by a fungus (or mold) called Aspergillus. The fungus is very common in both indoors and outdoors. Most people breathe in the spores of the fungus every day without being affected. But some people get the disease. It usually occurs in people with lung diseases or weakened immune systems.

Code history

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