D89.41: Monoclonal mast cell activation syndrome
D89.41, monoclonal mast cell activation syndrome, is listed as a covered diagnosis in 4 Medicare billing and coding articles that apply to 2 HCPCS Level II codes, including U0002 (2019-ncov coronavirus, sars-cov-2/2019-ncov (covid-19)…), U0001 (Cdc 2019 novel coronavirus (2019-ncov) real-time rt-pcr…). The articles come from 4 Medicare contractors. A listed diagnosis supports medical necessity only; coverage still depends on the LCD's criteria and on documentation in the medical record.
HCPCS Level II codes with D89.41 as a covered diagnosis
| Code | Description | Medicare coverage | DMEPOS fee 2026 (state range) | Articles listing it |
|---|---|---|---|---|
| U0002 | 2019-ncov coronavirus, sars-cov-2/2019-ncov (covid-19), any technique, multiple types or subtypes (includes all targets), non-cdc | Carrier judgment | — | 4 |
| U0001 | Cdc 2019 novel coronavirus (2019-ncov) real-time rt-pcr diagnostic panel | Carrier judgment | — | 4 |
Medicare policy articles listing D89.41
- A58710: Billing and Coding: MolDX: Molecular Syndromic Panels for Infectious Disease Pathogen Identification Testing (Palmetto GBA (MAC - Part A, MAC - Part B); 2 Level II codes). LCD with the same title: L38988, L39001, L39038, L39044
- A58720: Billing and Coding: MolDX: Molecular Syndromic Panels for Infectious Disease Pathogen Identification Testing (Noridian Healthcare Solutions, LLC (MAC - Part A, MAC - Part B); 2 Level II codes). LCD with the same title: L38988, L39001, L39038, L39044
- A58761: Billing and Coding: MolDX: Molecular Syndromic Panels for Infectious Disease Pathogen Identification Testing (WPS Insurance Corporation (MAC - Part A, MAC - Part B); 2 Level II codes). LCD with the same title: L38988, L39001, L39038, L39044
- A58747: Billing and Coding: MolDX: Molecular Syndromic Panels for Infectious Disease Pathogen Identification Testing (CGS Administrators, LLC (MAC - Part A, MAC - Part B); 2 Level II codes). LCD with the same title: L38988, L39001, L39038, L39044
A diagnosis listed as covered in a billing and coding article supports medical necessity for the article's codes; it does not guarantee payment. Coverage depends on the LCD's criteria, the contractor's jurisdiction and documentation in the medical record.
Other D89 diagnoses (Other disorders involving the immune mechanism, not elsewhere classified)
- D89.42 — Idiopathic mast cell activation syndrome
- D89.43 — Secondary mast cell activation
- D89.44 — Hereditary alpha tryptasemia
- D89.49 — Other mast cell activation disorder
- D89.0 — Polyclonal hypergammaglobulinemia
- D89.1 — Cryoglobulinemia
- D89.3 — Immune reconstitution syndrome
- D89.810 — Acute graft-versus-host disease
- D89.811 — Chronic graft-versus-host disease
- D89.812 — Acute on chronic graft-versus-host disease
- D89.813 — Graft-versus-host disease, unspecified
- D89.82 — Autoimmune lymphoproliferative syndrome [ALPS]
- D89.84 — IgG4-related disease
- D89.89 — Other specified disorders involving the immune mechanism, not…
Frequently asked questions
Does Medicare cover D89.41 (Monoclonal mast cell activation syndrome)?
Medicare covers items and services, not diagnoses. 4 Medicare billing and coding articles list D89.41 as a covered diagnosis for 2 HCPCS Level II codes: the diagnosis can support medical necessity for those codes, but payment still depends on the LCD's coverage criteria and the medical record.
Which HCPCS codes can be billed with ICD-10 D89.41?
The Level II codes from the policies most specific to this diagnosis are U0002 (2019-ncov coronavirus, sars-cov-2/2019-ncov (covid-19)…, 4 articles); U0001 (Cdc 2019 novel coronavirus (2019-ncov) real-time rt-pcr…, 4 articles). Code choice depends on the item supplied; check each code's descriptor.
Which Medicare policy articles list D89.41?
A58710 (Billing and Coding: MolDX: Molecular Syndromic Panels for Infectious Disease Pathogen Identification Testing); A58720 (Billing and Coding: MolDX: Molecular Syndromic Panels for Infectious Disease Pathogen Identification Testing); A58761 (Billing and Coding: MolDX: Molecular Syndromic Panels for Infectious Disease Pathogen Identification Testing), and 1 more article.
What is ICD-10-CM code D89.41?
D89.41 is the ICD-10-CM code for monoclonal mast cell activation syndrome, in category D89 (Other disorders involving the immune mechanism, not elsewhere classified), chapter 3: Diseases of the blood and immune mechanism.
Next steps
- Run a reimbursement report for a device billed under U0002
- Watch U0002 for fee, coverage and descriptor changes
- Build a full Medicare revenue model for U0002
Sources: CMS Medicare Coverage Database billing and coding articles (covered ICD-10 code lists and HCPCS links); ICD-10-CM FY2026; CMS HCPCS Level II release October 2026; CMS DMEPOS fee schedule 2026 (non-rural state fees). Not billing or legal advice.
Chapter 3: Diseases of the blood and immune mechanism · All diagnoses · HCPCS lookup