D49.9 Neoplasm of unspecified behavior of unspecified site

Billable ICD-10-CM code, FY2026.

Applies from D49 Neoplasms of unspecified behavior

Includes

• 'growth' NOS
• neoplasm NOS
• new growth NOS
• tumor NOS

Excludes1 (never code together)

• neoplasms of uncertain behavior (D37-D44, D48)

Notes

• Category D49 classifies by site neoplasms of unspecified morphology and behavior. The term 'mass', unless otherwise stated, is not to be regarded as a neoplastic growth.

MS-DRG index

Defines the logic of DRG(s) 826-828 in MDC 17.

Approximate ICD-9-CM (GEMs)

• 239.9 Neoplasm of unspecified nature, site unspecified

Code annotations containing back-references to D49.9

Back-references to D49

• Code First: D63.0 Anemia in neoplastic disease ("neoplasm (C00-D49)")
• Code First: G13.0 Paraneoplastic neuromyopathy and neuropathy ("underlying neoplasm (C00-D49)")
• Code First: G13.1 Other systemic atrophy primarily affecting central nervous system in neoplastic disease ("underlying neoplasm (C00-D49)")
• Code First: G32.8 Other specified degenerative disorders of nervous system in diseases classified elsewhere ("cerebral degeneration (due to) neoplasm (C00-D49)")
• Code First: G32.81 Cerebellar ataxia in diseases classified elsewhere ("cerebellar ataxia (in) neoplastic disease (paraneoplastic cerebellar degeneration) (C00-D49)")
• Code First: G53 Cranial nerve disorders in diseases classified elsewhere ("neoplasm (C00-D49)")
• Code First: G55 Nerve root and plexus compressions in diseases classified elsewhere ("neoplasm (C00-D49)")
• Code First: G63 Polyneuropathy in diseases classified elsewhere ("neoplasm (C00-D49)")
• Code First: G73.1 Lambert-Eaton syndrome in neoplastic disease ("underlying neoplasm (C00-D49)")
• Code First: G73.3 Myasthenic syndromes in other diseases classified elsewhere ("neoplasm (C00-D49)")
• Code First: G91.4 Hydrocephalus in diseases classified elsewhere ("neoplasm (C00-D49)")
• Code First: G99.2 Myelopathy in diseases classified elsewhere ("neoplasm (C00-D49)")
• Code First: I31.31 Malignant pericardial effusion in diseases classified elsewhere ("underlying neoplasm (C00-D49)")
• Code First: J91.0 Malignant pleural effusion ("underlying neoplasm (C00-D49)")
• Code First: M36.0 Dermato(poly)myositis in neoplastic disease ("underlying neoplasm (C00-D49)")

Diagnosis Index entries for D49.9

• Arthropathy › in (due to) › neoplastic disease NOS (see also Neoplasm)
• Ataxia, ataxy, ataxic › cerebellar (hereditary) › in › neoplastic disease
• Atrophy, atrophic (of) › systemic affecting central nervous system › in › neoplastic disease
• Compression › nerve › root or plexus NOS (in) › neoplastic disease
• Dermatomyositis (acute) (chronic) › in (due to) neoplastic disease
• Dermatopolymyositis › in neoplastic disease
• Encephalopathy (acute) › in (due to) (with) › neoplastic disease (see also Neoplasm)
• Myasthenia › syndrome › in › neoplastic disease
• Myelopathy (spinal cord) › in (due to) › neoplastic disease
• Neuromyopathy › paraneoplastic (see also, Neoplasm, by site, if known)
• Neuropathy, neuropathic › paraneoplastic (sensorial) (Denny Brown) (see also, Neoplasm, by site, if known)
• Osteitis › deformans › in (due to) › neoplastic disease
• Palsy › cranial nerve › multiple › in › neoplastic disease
• Polyneuropathy (peripheral) › in (due to) › neoplastic disease
• Syndrome › myasthenic › in › neoplastic disease

Nearby codes

• D49.6 Neoplasm of unspecified behavior of brain
• D49.7 Neoplasm of unspecified behavior of endocrine glands and other parts of nervous system
• D49.8 Neoplasm of unspecified behavior of other specified sites
• D49.81 Neoplasm of unspecified behavior of retina and choroid
• D49.89 Neoplasm of unspecified behavior of other specified sites
• D49.9 Neoplasm of unspecified behavior of unspecified site (this code)