D49.9 Neoplasm of unspecified behavior of unspecified site
The ICD-10-CM code for Neoplasm of unspecified behavior of unspecified site is D49.9 (FY2026). It is a billable, claim-ready diagnosis code.
Classification
- Chapter
- 2: Neoplasms (C00-D49)
- Section
- D49: Neoplasms of unspecified behavior (D49)
- Category D49
- 18 codes (14 billable)
- FY2026 Status
- Stable since FY2024
Also Known As
ICD-10-CM Alphabetic Index entries that lead to D49.9:
- Neuropathy, neuropathic › paraneoplastic (sensorial) (Denny Brown) (see also, Neoplasm, by site, if known)
- Dermatomyositis (acute) (chronic) › in (due to) neoplastic disease
- Neuromyopathy › paraneoplastic (see also, Neoplasm, by site, if known)
- Dermatopolymyositis › in neoplastic disease
- Polyneuropathy (peripheral) › in (due to) › neoplastic disease
- Encephalopathy (acute) › in (due to) (with) › neoplastic disease (see also Neoplasm)
- Myelopathy (spinal cord) › in (due to) › neoplastic disease
- Arthropathy › in (due to) › neoplastic disease NOS (see also Neoplasm)
U.S. Hospital Utilization
- An estimated 590 U.S. inpatient stays in 2023 included D49.9 among the documented diagnoses.
Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.
Official Coding Guidelines
Tx of primary site (TOC entry)a. Admission/Encounter for treatment of primary site ............................................................. 33
Tx of secondary site (TOC entry)b. Admission/Encounter for treatment of secondary site .......................................................... 33
Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026