G13.2Systemic atrophy primarily affecting the central nervous system in myxedema

G13.2 is the ICD-10-CM diagnosis code for systemic atrophy primarily affecting the central nervous system in myxedema. It belongs to category G13 (systemic atrophies primarily affecting central nervous system in diseases classified elsewhere), block G10-G14 (systemic atrophies primarily affecting the central nervous system) and chapter 6 (diseases of the nervous system). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within G13 (systemic atrophies primarily affecting central nervous system in diseases classified elsewhere), G13.2 is specifically for systemic atrophy primarily affecting the central nervous system in myxedema. Related codes cover Paraneoplastic neuromyopathy and neuropathy (G13.0), other systemic atrophy primarily affecting central nervous system in neoplastic disease (G13.1) and systemic atrophy primarily affecting central nervous system in other diseases classified elsewhere (G13.8).

Code first underlying disease, such as: hypothyroidism (E03.-) and myxedematous congenital iodine deficiency (E00.1).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 056 (Degenerative Nervous System Disorders with MCC, relative weight 2.2655) and DRG 057 (Degenerative Nervous System Disorders without MCC, relative weight 1.2838), in MDC 01 (Diseases and Disorders of the Nervous System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It is a manifestation code, so it describes the effect of an underlying disease and can't be the principal diagnosis. Code the underlying condition first.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 331.7 (cerebral degeneration in diseases classified elsewhere).