Listing 11.13 in 2026: Muscular Dystrophy SSDI Claims Under Paragraph A Disorganization of Motor Function in Two Extremities With Extreme Limitation and Paragraph B Marked Physical Limitation Plus Marked Limitation in Understanding Remembering or Applying Information, Interacting With Others, Concentrating Persisting or Maintaining Pace, or Adapting or Managing Oneself

Muscular dystrophy claims are some of the strongest neurological files SSA sees, but they still get denied when the record doesn't line up with Listing 11.13. Every MD subtype has a distinct pattern of weakness, distinct genetic testing, and a distinct progression curve. If your file treats muscular dystrophy as one thing instead of a family of specific diseases, adjudicators can miss what they need to allow.

This guide walks you through the verbatim text of Listing 11.13, what SSA means by motor disorganization and extreme limitation in the MD setting, how Paragraph B pairs a marked physical limitation with a marked mental limitation, and how each of the common dystrophies (Duchenne, Becker, myotonic type 1 and 2, facioscapulohumeral, limb-girdle, oculopharyngeal, Emery-Dreifuss) fits into the framework. It closes with two worked examples.

The Verbatim Text of Listing 11.13

SSA's Listing 11.13 in 2026 reads as follows under 20 CFR Part 404, Subpart P, Appendix 1:

A or B. You do not need both. The paragraphs mirror Listing 11.07 (cerebral palsy) and Listing 11.09 (multiple sclerosis), so a lawyer working across neurological files sees the same structure repeat.

What SSA Means by Motor Disorganization in Muscular Dystrophy

Section 11.00D1 defines significant motor disorganization as interference with movement of two extremities that results, despite prescribed treatment, in a sustained disturbance of gross and dexterous movements or gait and station. MD produces this pattern reliably. Progressive muscle fiber loss reduces force generation. That produces weakness in specific muscle groups that varies by subtype.

Two extremities means any two, so an MD claimant with pelvic girdle weakness affecting both legs, or a claimant with scapular winging plus proximal arm weakness affecting both arms, or a claimant with mixed distal-and-proximal weakness in one arm and one leg, all meet the two-extremity element.

Duchenne Muscular Dystrophy (DMD)

Dystrophin gene mutations on the X chromosome. Almost exclusively males. Symptom onset by age 5. Loss of ambulation typically by age 12 without treatment, later with corticosteroids like deflazacort or prednisone. Many patients now reach age 30 to 40 with ventilator support and cardiac management. Adults with DMD are almost always Paragraph A because they lost independent standing and ambulation years ago.

Becker Muscular Dystrophy (BMD)

Same dystrophin gene but with partial function. Symptom onset later, usually 5 to 15. Loss of ambulation typically in the 30s to 50s. Cardiomyopathy is a leading cause of morbidity. Some adults with BMD walk into their 40s and 50s with a Trendelenburg gait, calf pseudohypertrophy, and progressive hip and knee extensor weakness.

Myotonic Dystrophy Type 1 (DM1)

CTG repeat expansion in the DMPK gene. Multisystem disease. Distal weakness, myotonia (delayed muscle relaxation), frontal balding, cataracts, cardiac conduction defects, insulin resistance, cognitive slowing. Adult-onset form manifests 20s to 40s. The cognitive piece drives Paragraph B for many DM1 claimants.

Myotonic Dystrophy Type 2 (DM2)

CCTG repeat expansion in the CNBP gene. Proximal weakness (hip and shoulder girdle), myotonia less prominent than DM1, less cognitive involvement. Often diagnosed in the 40s to 60s.

Facioscapulohumeral Muscular Dystrophy (FSHD)

D4Z4 contraction on chromosome 4q35 for FSHD1 or SMCHD1 mutation for FSHD2. Asymmetric facial weakness, scapular winging, biceps and triceps weakness with relative sparing of deltoid, plus foot drop and abdominal weakness. Adult-onset. Highly variable. Some patients walk independently for life. Others are wheelchair-dependent by age 40.

Limb-Girdle Muscular Dystrophy (LGMD)

Over 30 recognized genetic subtypes. Common ones include LGMD R1 (calpain), R2 (dysferlin), R9 (FKRP). All produce hip and shoulder girdle weakness. Ages of onset span childhood to late middle age depending on subtype.

Oculopharyngeal Muscular Dystrophy (OPMD)

PABPN1 GCN repeat expansion. Late-onset, typically 40s to 60s. Ptosis, dysphagia, proximal limb weakness. Common in French Canadian and Bukhara Jewish populations.

Emery-Dreifuss Muscular Dystrophy (EDMD)

EMD or LMNA gene mutations. Early joint contractures (elbow, ankle, spine), humeroperoneal weakness, and cardiac conduction defects that require pacemakers or defibrillators. Onset in childhood to early adulthood.

Paragraph A: Extreme Limitation

Section 11.00D2 defines extreme limitation. Extreme means an inability to stand up from a seated position without assistance, or an inability to maintain balance while standing or walking without an assistive device, or an inability to use the upper extremities to independently initiate, sustain, and complete work-related activities involving fine and gross movements.

Stand Up From Seated

MD adults who cannot rise from a chair without pushing off with both arms, without a lift-assist chair, or without help from another person meet this criterion. The Gowers sign (using the arms to walk up the legs) is a classic finding in DMD, BMD, and severe LGMD. It's also a formal medical sign an examiner can document.

Balance While Standing or Walking

Adults with FSHD foot drop, DM1 distal weakness, or advanced LGMD often use bilateral canes, a walker, or a wheelchair. Fall frequency above two per month, use of ankle-foot orthoses (AFOs), or documented gait analysis showing base of support instability all support extreme limitation here.

Upper Extremity Fine and Gross Movement

MACS-equivalent scoring works well here. If you can't lift a gallon of milk to counter height, can't fasten buttons, can't sustain a pinch on a pen for a full sentence, and can't sustain a keyboard task longer than 10 minutes without pain or fatigue that halts you, that's extreme limitation.

Paragraph B: Marked Physical Plus Marked Mental

Paragraph B is where DM1 and cognitively-involved dystrophies win. Marked is more than moderate but less than extreme. You need marked in physical (11.00G3a) plus marked in one of four mental areas (11.00G3b).

Marked Physical Limitation

Any MD claimant with GMFCS-equivalent Level II or III walking with an assistive device, or someone who can walk short distances but cannot sustain standing for a full workday, meets marked physical. The 6-minute walk test below 300 meters is a useful objective marker. So is a Vignos scale of 3 to 6 (walks with assistance to wheelchair-dependent) or a Brooke upper extremity scale of 3 to 4.

Understanding, Remembering, or Applying Information

DM1 patients often score 10 to 20 points below their premorbid IQ on formal testing because of CTG-repeat-length-correlated cognitive changes. If your neuropsych evaluation shows a Full-Scale IQ in the 70s or a Processing Speed Index in the low 70s or below, that supports marked limitation here.

Interacting With Others

DM1 apathy and mood-related isolation are well-documented. Facial masking, ptosis, and dysarthria in advanced disease reduce social interaction. If you have documented difficulty relating to supervisors, coworkers, or the public because of these features, that area applies.

Concentrating, Persisting, or Maintaining Pace

DM1 sleep-disordered breathing produces daytime hypersomnia. Central sleep apnea and hypercapnia related to diaphragm weakness reduce cognitive endurance. If your polysomnogram shows an AHI above 15 or documented daytime sleepiness with Epworth score above 12, that supports this area.

Adapting or Managing Oneself

Depression rates in MD adults run 20 to 40 percent depending on subtype. Documented anxiety, depression, or emotional dysregulation from a treating psychiatrist or psychologist that limits work self-management fits here.

The Diagnostic Evidence SSA Wants

Creatine Kinase (CK)

CK elevation supports muscle fiber destruction. DMD and severe LGMD often show CK values 10x to 200x normal. BMD shows 5x to 50x. FSHD is usually less than 5x. DM1 and DM2 can be near normal or mildly elevated. A modestly elevated CK does not rule out MD.

Genetic Testing

Modern MD workups start with a next-generation sequencing panel that covers 30 to 100 genes. For DMD/BMD, the sequence is deletion/duplication testing first, then sequencing. For DM1 and DM2, CTG and CCTG repeat sizing. For FSHD, D4Z4 restriction mapping or SMCHD1 sequencing. SSA does not require a genetic diagnosis, but a confirmed molecular result strengthens the file and forecloses adjudicator questions about differential diagnoses.

Muscle Biopsy

Less commonly needed with modern genetics, but a biopsy showing dystrophic changes, absent dystrophin (DMD), reduced dystrophin (BMD), or subtype-specific findings can be decisive when genetic testing is inconclusive.

Electrodiagnostic Studies

EMG shows myopathic units in most MD subtypes and myotonic discharges in DM1 and DM2. Nerve conduction studies are typically normal in classic MD (distinguishing it from motor neuron disease and peripheral neuropathy).

Cardiac Testing

DMD, BMD, DM1, EDMD, and some LGMD subtypes involve cardiac muscle. Annual echocardiogram, EKG, and Holter or event monitor findings help document combined cardiopulmonary limitation. Cardiac MRI with late gadolinium enhancement is now standard for adult MD patients.

Pulmonary Function

Forced vital capacity (FVC) below 40 percent predicted is a marker of impending respiratory failure in DMD and other rapidly progressive dystrophies. Non-invasive ventilation dependence is a strong indicator of extreme limitation regardless of ambulatory status.

How Adult MD Claims Compare to Other Neurological Listings

Listing 11.13 differs from Listing 11.09 (MS) because MD is progressive but not relapsing-remitting. It differs from Listing 11.10 (ALS) because MD is a muscle disease, not a motor neuron disease. It differs from Listing 11.14 (peripheral neuropathy) because MD spares the peripheral nerves. And it differs from Listing 11.07 (cerebral palsy) because MD is progressive rather than static.

If your file could also meet another listing, plead both. A DM1 claimant with severe cognitive limitation can plead Listing 11.13 and Listing 12.02 (neurocognitive disorders) concurrently. A DMD claimant on nocturnal BiPAP with FVC 25 percent can plead 11.13 and Listing 3.02 (chronic respiratory disorders).

How Adjudicators Handle MD Files

DDS medical consultants typically know MD basics but not subtype nuances. If your file involves a rare LGMD subtype or OPMD, include a one-page cover memo from your neurologist that explains the specific pattern and prognosis. Reference the genetic testing report and its confirmed mutation.

Adjudicators look for four elements:

1. Confirmed MD diagnosis with subtype and molecular basis
2. Functional documentation matching either Paragraph A extreme limitation or Paragraph B marked physical
3. Paragraph B mental documentation (neuropsych or psychiatric records) if pleading B
4. Response to prescribed treatment as required by 11.00K adherence rules

Prescribed treatment in MD includes corticosteroids (deflazacort, prednisone) for DMD/BMD, mexiletine for myotonia in DM1, non-invasive ventilation for respiratory failure, ACE inhibitors and beta blockers for cardiomyopathy, and physical therapy across all subtypes. Adherence with these is expected.

Worked Example: Daniel, 27, Cambridge MA, Duchenne Muscular Dystrophy

Worked Example: Sofia, 48, Miami FL, Myotonic Dystrophy Type 1

Common Denial Reasons and How to Prevent Them

Missing Genetic Confirmation

Older MD diagnoses were often clinical or biopsy-based without genetic confirmation. If your file lacks a molecular diagnosis, ask your neurologist to order a next-generation sequencing panel through a lab like Invitae or Blueprint Genetics. Many labs offer no-cost testing under sponsored programs. A confirmed mutation removes any adjudicator doubt about whether MD is really the diagnosis.

Weak Functional Documentation

Neurology visit notes that say "generalized weakness, needs assistance for ADLs" are too vague. Ask your neurologist or PT to document specific measures such as 6-minute walk distance, Brooke upper extremity scale, Vignos lower extremity scale, or manual muscle testing grades. These are the numbers adjudicators plug into their listing analysis.

No Mental Health Documentation for Paragraph B

DM1 claimants often assume that cognitive slowing is obvious to family and doctors but never get formal neuropsychological testing. Without formal testing, adjudicators cannot score marked limitation. Request a neuropsych referral early in your claim process.

Frequently Asked Questions