Listing 11.17 in 2026: Neurodegenerative Disorders of the Central Nervous System SSDI Claims Under Paragraph A Disorganization of Motor Function in Two Extremities With Extreme Limitation and Paragraph B Marked Physical Plus Marked Mental Limitation for Huntington Disease, Spinocerebellar Ataxias, Fragile X-Associated Tremor Ataxia Syndrome, Progressive Supranuclear Palsy, and Related Rare Diseases

Listing 11.17 is the catch-all for progressive neurodegenerative diseases of the central nervous system that don't fit under other Blue Book neurological listings. It's the rule your neurologist reaches for when your diagnosis is Huntington disease, spinocerebellar ataxia type 1, 2, 3, 6, or 7, fragile X-associated tremor ataxia syndrome (FXTAS), progressive supranuclear palsy, corticobasal degeneration, multiple system atrophy of either type, or a similar rare progressive brain disease.

SSA's Compassionate Allowance list already includes several of these conditions (Huntington disease with adult onset, corticobasal degeneration, progressive supranuclear palsy, multiple system atrophy, and certain SCA subtypes), which means files often move fast. But not every claimant benefits from CAL processing automatically. You still need documentation that meets Paragraph A or Paragraph B.

This guide walks you through the verbatim text of Listing 11.17, defines what SSA means by motor disorganization and extreme limitation in the neurodegenerative context, breaks down Paragraph B's marked physical plus marked mental structure, and explains how each of the common qualifying diseases fits into the framework. Two worked examples close the piece.

The Verbatim Text of Listing 11.17

SSA's Listing 11.17 in 2026 reads as follows under 20 CFR Part 404, Subpart P, Appendix 1:

Paragraph A or Paragraph B satisfies the listing. The verbatim examples in the listing text (Huntington disease, Friedreich ataxia, spinocerebellar degeneration) are illustrative, not exhaustive. Adjudicators apply the listing to any similar progressive neurodegenerative disease with the documented functional pattern.

Which Diseases Fit Under Listing 11.17

Huntington Disease (HD)

Autosomal dominant CAG trinucleotide expansion in the HTT gene. Chorea, cognitive decline, and psychiatric symptoms in a classic triad. Adult onset typically 30s to 50s. Rare juvenile-onset form has more rigidity and less chorea. Huntington disease with adult onset is on SSA's Compassionate Allowance list, so files marked as HD move to expedited processing at the initial DDS level. Progressive functional decline is inevitable, and most HD patients meet Paragraph B within 5 to 10 years of clinical diagnosis, and Paragraph A within 10 to 15 years.

Friedreich Ataxia (FRDA)

Autosomal recessive GAA repeat expansion in the FXN gene. Progressive ataxia, dysarthria, loss of proprioception, cardiomyopathy, scoliosis, diabetes mellitus in about 30 percent, and pes cavus foot deformity. Onset typically before age 25. Wheelchair use by 10 to 15 years after diagnosis. Many patients also meet Listing 4.02 for cardiomyopathy concurrently. Omaveloxolone (Skyclarys) was FDA-approved in 2023 for FRDA and slows progression modestly, but does not prevent listing-level disability.

Spinocerebellar Ataxias (SCA)

Autosomal dominant. Over 40 recognized subtypes. SCA1, SCA2, SCA3 (Machado-Joseph disease), SCA6, and SCA7 are the most common. All involve progressive cerebellar ataxia. SCA2 and SCA3 include motor neuron involvement. SCA7 includes retinal degeneration. Ages of onset span teens to 60s depending on repeat length. Wheelchair use typically 10 to 20 years from onset.

Fragile X-Associated Tremor Ataxia Syndrome (FXTAS)

Adult-onset disease in premutation carriers of the FMR1 gene (55 to 200 CGG repeats). Intention tremor, cerebellar ataxia, executive dysfunction, autonomic dysfunction, and peripheral neuropathy. Typical onset age 60. Progresses over 5 to 15 years. Mostly affects men, but women can develop mild forms.

Progressive Supranuclear Palsy (PSP)

Tauopathy. Vertical gaze palsy, axial rigidity, early falls, pseudobulbar affect, and executive dysfunction. Mean survival from symptom onset is 6 to 9 years. PSP is on SSA's Compassionate Allowance list.

Corticobasal Degeneration (CBD)

Tauopathy. Asymmetric rigidity and apraxia, alien limb phenomenon, cortical sensory loss, and progressive aphasia in some presentations. Mean survival 6 to 8 years. On CAL list.

Multiple System Atrophy (MSA)

Alpha-synucleinopathy. Two clinical types. MSA-P is parkinsonian predominant. MSA-C is cerebellar predominant. Both feature severe autonomic failure, cognitive preservation until late, and rapid progression. Mean survival 7 to 10 years. On CAL list.

Dentatorubral-Pallidoluysian Atrophy (DRPLA)

Autosomal dominant CAG expansion in the ATN1 gene. Ataxia, choreoathetosis, myoclonus epilepsy, and dementia. More common in Japanese populations.

Adult-Onset Leukodystrophies

Adult polyglucosan body disease, adult-onset autosomal dominant leukodystrophy (ADLD), and X-linked adrenoleukodystrophy (AMN form in adults) all fit Listing 11.17 when they produce the required motor and cognitive limitations.

Motor Disorganization Under 11.00D1

Neurodegenerative diseases produce a variety of motor patterns. Huntington disease produces chorea (involuntary, dance-like movements) plus later rigidity and bradykinesia. SCAs produce cerebellar ataxia with wide-based gait, dysmetria on finger-to-nose, dysdiadochokinesia, and intention tremor. FXTAS produces intention tremor plus ataxia. PSP produces axial rigidity, early falls, and vertical gaze palsy that impair navigation. CBD produces asymmetric limb rigidity plus apraxia (loss of purposeful movement). MSA-P produces parkinsonism plus autonomic failure. MSA-C produces ataxia plus autonomic failure.

Any of these that involves two extremities and produces a sustained disturbance of gross and dexterous movements or gait and station meets 11.00D1.

Paragraph A: Extreme Limitation

Stand Up From Seated

PSP patients frequently fall backward when rising from a chair (retropulsion sign). MSA-P and advanced HD patients often cannot rise without arm support. CBD patients with asymmetric leg rigidity struggle to rise on their affected side. Any of these patterns, when documented by neurology or PT, supports extreme limitation in the stand-up sub-domain.

Balance While Standing or Walking

Wide-based ataxic gait, frequent falls (more than 2 per month is a useful threshold), and use of a walker, bilateral canes, or wheelchair all support extreme limitation here. Neurology visit notes documenting Berg Balance Scale below 40, Tinetti score below 19, or falls history are all useful.

Upper Extremity Fine and Gross Movement

Intention tremor in SCAs, FXTAS, and MSA-C prevents accurate reaching and manipulation. Apraxia in CBD prevents purposeful upper extremity use even when strength is preserved. Chorea in HD interferes with sustained fine motor tasks. Any of these that prevents work-related fine and gross movements supports extreme limitation.

Paragraph B: Marked Physical Plus Marked Mental

Paragraph B is often the winning path for HD, FXTAS, CBD, and PSP files because these diseases combine physical and cognitive limitation early. Marked physical limitation from ataxia or rigidity plus marked mental limitation in one of four areas is enough.

Understanding, Remembering, or Applying Information

HD produces subcortical dementia with executive dysfunction and working memory loss. FXTAS produces executive dysfunction, sometimes mild dementia. CBD and PSP produce frontal-subcortical cognitive slowing. Neuropsychological testing that shows executive function scores below the second percentile, working memory below the fifth percentile, or full-scale IQ decline from premorbid estimate supports marked limitation.

Interacting With Others

HD patients experience irritability, apathy, and impulsivity that impair workplace interactions. PSP patients experience pseudobulbar affect (uncontrollable laughing or crying) that disrupts social contexts. Documented psychiatric or behavioral consultations supporting these limitations qualify.

Concentrating, Persisting, or Maintaining Pace

Bradyphrenia (slow thinking) is a hallmark of PSP, CBD, and advanced HD. Formal neuropsych testing showing processing speed below the fifth percentile or sustained attention below the fifth percentile supports marked limitation.

Adapting or Managing Oneself

HD is associated with depression rates above 40 percent and suicide rates 5 to 10 times the general population. FXTAS and MSA are associated with clinically significant depression. Documented mental health treatment for a mood or anxiety disorder that limits work-related self-management supports this area.

Compassionate Allowance Processing

Several Listing 11.17 diseases are on SSA's Compassionate Allowance (CAL) list. These include Huntington disease with adult onset, progressive supranuclear palsy, corticobasal degeneration, multiple system atrophy, and some spinocerebellar ataxia subtypes. When you file, use the exact CAL name in Section 3 of the SSDI application (Medical Conditions).

CAL processing means DDS flags the file for expedited review. Initial decisions can be issued in days rather than months when medical evidence is complete at filing. To get the fastest possible processing, include with your application:

• Genetic test report confirming the diagnosis (HD, SCA, FXTAS) or specialist letter confirming the clinical diagnosis (PSP, CBD, MSA)
• Neurology visit notes from the past 12 months
• Any brain MRI reports (midbrain atrophy on MRI supports PSP; putaminal atrophy supports MSA-P; cerebellar atrophy supports SCA and MSA-C)
• Functional documentation from PT, OT, or SLP
• Any neuropsychological testing

Diagnostic Evidence SSA Wants

Genetic Testing

Modern practice is to obtain gene-specific testing when a familial pattern is present. HTT for HD, FMR1 for FXTAS, expanded panels for SCA subtypes, ATN1 for DRPLA, FXN for Friedreich ataxia. A confirmed molecular diagnosis is decisive.

Brain MRI

Findings that support specific diagnoses:

• Hummingbird sign or penguin sign of midbrain atrophy in PSP
• Putaminal atrophy with rim hyperintensity in MSA-P
• Hot cross bun sign in the pons in MSA-C
• Caudate atrophy in HD
• Cerebellar and brainstem atrophy in SCAs
• Middle cerebellar peduncle T2 hyperintensity in FXTAS
• Asymmetric parietal cortical atrophy in CBD

Neuropsychological Evaluation

Essential for Paragraph B claims. Should cover full-scale IQ, executive function (Trail Making Test, Wisconsin Card Sorting), working memory, processing speed, verbal fluency, and mood.

Autonomic Testing

For MSA and FXTAS files, tilt-table testing, sudomotor axon reflex testing (QSART), and Valsalva ratio provide objective evidence of autonomic failure. Orthostatic hypotension defined as a drop of 20 mmHg systolic or 10 mmHg diastolic within 3 minutes of standing supports the diagnosis.

How Adjudicators Handle Listing 11.17 Files

DDS medical consultants read Listing 11.17 files closely because the diseases are rare and the diagnoses often lay outside general neurology practice. If your case involves an uncommon SCA subtype or a leukodystrophy, include a one-page cover memo from your neurologist that explains the diagnosis, the expected progression, and the current functional limitations. Reference the imaging and genetic findings.

Common adjudicator questions:

• Is the diagnosis truly neurodegenerative, or is this a static process?
• Is the functional loss documented at extreme (Paragraph A) or marked (Paragraph B) level?
• For Paragraph B, is the mental limitation documented by neuropsych testing?
• Has the claimant adhered to prescribed treatment where applicable?

Answer each of these preemptively in your file to prevent unnecessary consultative exams.

Worked Example: Rachel, 45, Boston MA, Huntington Disease

Worked Example: David, 58, Fort Lauderdale FL, Progressive Supranuclear Palsy

Common Denial Reasons and How to Prevent Them

Missing Genetic or Specialist Confirmation

Some 11.17 files rely on primary care documentation only. That's rarely enough. Get a movement disorder specialist or a neurogenetics clinic visit. Their diagnostic letter carries significantly more weight with adjudicators than a general neurologist's notes.

Insufficient Functional Documentation

Adjudicators need specifics. "Ataxia limits her walking" is not enough. What SSA wants is 6-minute walk distance, Berg Balance Scale, Tinetti score, or a documented fall diary. For upper extremity limitation, ask OT to score specific work-related tasks.

No Neuropsychological Testing for Paragraph B

If you're pleading Paragraph B, you need formal testing. Without it, adjudicators cannot verify marked mental limitation. Ask your neurologist for a neuropsychology referral early in your claim.

File Not Flagged as CAL

If your diagnosis is on the Compassionate Allowance list, use the exact CAL name on the application. Some files don't get flagged because the applicant wrote a generic term instead of the specific CAL name.

Frequently Asked Questions