ICD-10 Code G12.23 – Primary lateral sclerosis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G12.23 – Primary lateral sclerosis
What it is
Primary lateral sclerosis is a rare motor neuron disease that mainly affects the upper motor neurons. It causes progressive stiffness and weakness, usually without the lower motor neuron findings seen in other ALS-spectrum disorders.
Clinical signs
Common findings include spasticity, slowed movements, and increased reflexes. Clinical features vary; refer to documentation, and note that symptoms often progress gradually over time.
When to use this code
Use G12.23 when the provider documents primary lateral sclerosis by name or clearly describes a diagnosis of PLS. Apply it for confirmed cases in neurology notes, discharge summaries, or problem lists when the condition is being actively managed or followed.
Choose the code when documentation supports an upper motor neuron syndrome consistent with PLS and excludes other causes. If the record is unclear or the diagnosis is tentative, check documentation before coding.
Do not use for
Do not use this code for amyotrophic lateral sclerosis, spinal muscular atrophy, or other motor neuron diseases unless PLS is specifically documented. Avoid using it for nonspecific weakness or spasticity without a confirmed diagnosis.
Coding tip
Code from the provider’s stated diagnosis, and query if the note describes progressive spastic weakness but does not clearly name primary lateral sclerosis.