D49.6 Neoplasm of unspecified behavior of brain

Billable ICD-10-CM code, FY2026.

Excludes1 (never code together)

• neoplasm of unspecified behavior of cerebral meninges (D49.7)
• neoplasm of unspecified behavior of cranial nerves (D49.7)

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.

Risk adjustment (HCC)

• CMS-HCC V28: HCC 23 — Prostate, Breast, and Other Cancers and Tumors
• CMS-HCC V22: HCC 12 — Breast, Prostate, and Other Cancers and Tumors
• RxHCC V08: HCC 22 — Prostate, Breast, Bladder, and Other Cancers and Tumors
• ESRD V24: HCC 12

MS-DRG index

Defines the logic of DRG(s) 054-055 in MDC 01.

Approximate ICD-9-CM (GEMs)

• 239.6 Neoplasm of unspecified nature of brain

Code annotations containing back-references to D49.6

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 D49.6

• Degeneration, degenerative › brain (cortical) (progressive) › in › neoplastic disease

Nearby codes

• D49.51 Neoplasm of unspecified behavior of kidney
• D49.511 Neoplasm of unspecified behavior of right kidney
• D49.512 Neoplasm of unspecified behavior of left kidney
• D49.519 Neoplasm of unspecified behavior of unspecified kidney
• D49.59 Neoplasm of unspecified behavior of other genitourinary organ
• D49.6 Neoplasm of unspecified behavior of brain (this code)
• 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