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B45.3 ICD-10-CM Code: Osseous cryptococcosis

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Coding at a Glance

Tabular directives
2 Excludes2
Risk adjustment
CMS-HCC V28: 1 category · CMS-HCC V22 category 6 · RxHCC V08 category 5

Inpatient Payment Groups (MS-DRG)

Potential MS-DRG participation — not a DRG assignment.

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v43, Appendix B.

  • MS-DRG 791 — PREMATURITY WITH MAJOR PROBLEMS (MDC 15)
  • MS-DRG 793 — FULL TERM NEONATE WITH MAJOR PROBLEMS (MDC 15)
  • MS-DRG 867 — OTHER INFECTIOUS AND PARASITIC DISEASES DIAGNOSES WITH MCC (MDC 18)
  • MS-DRG 868 — OTHER INFECTIOUS AND PARASITIC DISEASES DIAGNOSES WITH CC (MDC 18)
  • MS-DRG 869 — OTHER INFECTIOUS AND PARASITIC DISEASES DIAGNOSES WITHOUT CC/MCC (MDC 18)
  • MS-DRG 974 — HIV WITH MAJOR RELATED CONDITION WITH MCC (MDC 25)
  • MS-DRG 975 — HIV WITH MAJOR RELATED CONDITION WITH CC (MDC 25)
  • MS-DRG 976 — HIV WITH MAJOR RELATED CONDITION WITHOUT CC/MCC (MDC 25)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Risk Adjustment (CMS-HCC)

Payment categories this diagnosis maps to under CMS-HCC V28, payment year 2026.

  • HCC 6 — Opportunistic Infections

Other models: CMS-HCC V22 HCC 6 · RxHCC V08 HCC 5

Risk scores depend on the enrollee's full accepted diagnosis set and segment; a category mapping alone does not determine payment.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for B45.3 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2026Effective: October 1, 2025

Notes without a marker are published on B45.3 itself; “inherited from” names the category or block whose note applies here.

Excludes2 — Not Included Here

Conditions not covered by this code, but which may be reported alongside it when both are present.

Source: inherited from B35-B49

Coder workflow for B45.3

MedCoder structured workflow — derived from this code’s own official record

Documentation check

The provider’s diagnostic statement
Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).

Official instructions as workflow

  • Excludes2 — not part of B45.3(2 notes)

    Coding workflow: The conditions named in this note are not included in B45.3. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

    CompareJ67, C84.0

    See the official tabular notes · Guidelines I.A.12.b

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Code Overview

Osseous cryptococcosis is a billable ICD-10-CM diagnosis code (B45.3).

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Indexed Clinical Terms (2)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

Verify Before Coding

  • CC as a secondary diagnosis (FY2026). Can raise the stay's MS-DRG severity tier.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

Other codes that name B45.3 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 1 Excludes1 note: M90 — Osteopathies in diseases classified elsewhere.

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

Referenced by 1 Code First instruction: M01 — Direct infections of joint in infectious and parasitic diseases classified elsewhere (via B45.-).

Each of these codes carries a Code First note naming this condition — when that code is reported, THIS code is sequenced first, ahead of it.

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

FY2026 MS-DRG: CC — Complication or Comorbidity. Reported as a secondary diagnosis, this code raises the stay's MS-DRG severity tier — except when the principal diagnosis is one of 12 clinically related codes on its CMS exclusion list. Does not count toward severity when the stay groups to DRGs 974-976 (HIV with Major Related Condition).

Named in the grouper logic of 8 MS-DRGs: DRG 791 (MDC 15), DRG 793 (MDC 15), DRG 867 (MDC 18), DRG 868 (MDC 18), DRG 869 (MDC 18), DRG 974 (MDC 25), DRG 975 (MDC 25), DRG 976 (MDC 25).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):INF004 — Fungal infections (default).

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical process (MS-DRG)

Acts as CC — raises the severity of other admissions. CMS groups these diagnoses into one MS-DRG principal-diagnosis exclusion process — a CC/MCC on this list never raises severity when the principal diagnosis is also on it.

B45.0 — Pulmonary cryptococcosis, B45.2 — Cutaneous cryptococcosis, B45.7 — Disseminated cryptococcosis, B45.8 — Other forms of cryptococcosis, B45.9 — Cryptococcosis, unspecified, B48.3 — Geotrichosis, B49 — Unspecified mycosis, B92 — Sequelae of leprosy, B94.2 — Sequelae of viral hepatitis, B94.8 — Sequelae of other specified infectious and parasitic diseases, B94.9 — Sequelae of unspecified infectious and parasitic disease

Same CMS-HCC risk category (V28)

CMS maps these diagnoses to the same Hierarchical Condition Category (Opportunistic Infections) for risk-adjusted payment.

B37.81 — Candidal esophagitis, B44.0 — Invasive pulmonary aspergillosis, B44.1 — Other pulmonary aspergillosis, B44.2 — Tonsillar aspergillosis, B44.7 — Disseminated aspergillosis, B44.89 — Other forms of aspergillosis, B44.9 — Aspergillosis, unspecified, B45.0 — Pulmonary cryptococcosis, B45.1 — Cerebral cryptococcosis, B45.2 — Cutaneous cryptococcosis, B45.7 — Disseminated cryptococcosis, B45.8 — Other forms of cryptococcosis, B45.9 — Cryptococcosis, unspecified, B46.0 — Pulmonary mucormycosis, B46.1 — Rhinocerebral mucormycosis, B46.2 — Gastrointestinal mucormycosis, B46.3 — Cutaneous mucormycosis, B46.4 — Disseminated mucormycosis, B46.5 — Mucormycosis, unspecified, B46.8 — Other zygomycoses, +16 more

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Fungal infections).

B44.0 — Invasive pulmonary aspergillosis, B44.1 — Other pulmonary aspergillosis, B44.2 — Tonsillar aspergillosis, B44.7 — Disseminated aspergillosis, B44.81 — Allergic bronchopulmonary aspergillosis, B44.89 — Other forms of aspergillosis, B44.9 — Aspergillosis, unspecified, B45.0 — Pulmonary cryptococcosis, B45.1 — Cerebral cryptococcosis, B45.2 — Cutaneous cryptococcosis, B45.7 — Disseminated cryptococcosis, B45.8 — Other forms of cryptococcosis, B45.9 — Cryptococcosis, unspecified, B46.0 — Pulmonary mucormycosis, B46.1 — Rhinocerebral mucormycosis, B46.2 — Gastrointestinal mucormycosis, B46.3 — Cutaneous mucormycosis, B46.4 — Disseminated mucormycosis, B46.5 — Mucormycosis, unspecified, B46.8 — Other zygomycoses, +86 more

Lab tests where this diagnosis supports Medicare coverage (NCD)

Medicare's National Coverage Determination (NCD) program lists this diagnosis as medical justification for these lab tests.

HIV Screening Test

Contextual Map

Every relationship of B45.3 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run B45.3 with these 2 related codes in Claim Check

Hierarchy

Referenced by Excludes1 notes

Referenced by Code First instructions

Clinical classification (CCSR)

Risk adjustment (CMS-HCC)

  • HCC 6 — Opportunistic Infections [CMS-HCC]— CMS-HCC V28 · 2026

MS-DRG Grouper

MDC crossing

  • MDC 15 — Newborns and Other Neonates with Conditions Originating in Perinatal Period[MDC crossing]: “Newborns and Other Neonates with Conditions Originating in Perinatal Period — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs.”— CMS MS-DRG Definitions Manual · FY2026
  • MDC 18 — Infectious and Parasitic Diseases, Systemic or Unspecified Sites[MDC crossing]: “Infectious and Parasitic Diseases, Systemic or Unspecified Sites — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 1 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026

Index entries

  • Cryptococcosis, cryptococcus (infection) (neoformans), bone[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Cryptococcosis, cryptococcus (infection) (neoformans), osseous[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data
CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page
Inpatient payment groups Official source data
CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v43 Release, file and checksum · Publisher’s page
Risk adjustment Official source data
2026 Mid-Year Final ICD-10 Mappings + Model Software (cms.gov/files/zip/2026-midyear-final-icd-10-mappings.zip, 2026-midyear-final-model-software.zip) — CMS-HCC V28, PY2026 mid-year final release Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder structured relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Cite this page

Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.

MedCoder.ai. "B45.3 — Osseous cryptococcosis." ICD-10-CM FY2026. https://medcoder.ai/icd10/code/b45.3-osseous-cryptococcosis

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Osseous cryptococcosis

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027 (effective October 1, 2026), and none are recorded for this code. Note changes are tracked from FY2027 only.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to B45.3 in its code family, with their registry titles.

View all codes in the B45 family