Listing 11.09 Multiple Sclerosis in 2026: How Social Security Decides MS SSDI Claims Under Paragraph A Two-Extremity Motor Disorganization or Paragraph B Marked Physical Plus Marked Mental Limitation in One of Four Areas

By Anthony Albert, Benefits Research Director, Disability Exchange · Updated June 28, 2026 · SSA Blue Book Section 11.00 Neurological (Adult)

Multiple sclerosis is one of the most common neurological listings claimants file under, and it is also one of the most miscategorized. SSA does not care that you have an MS diagnosis. It cares whether your MS produces either a specific motor disorganization pattern, or a specific combination of physical and mental limitation that meets Listing 11.09. The diagnosis is the price of admission. The win is in the documentation.

This guide walks the entire 11.09 path. We cover both Paragraph A and Paragraph B with the verbatim regulatory text, the SSA definitions of the words inside that text (disorganization, extreme limitation, marked limitation), the McDonald 2024 diagnostic criteria SSA looks for in the file, the EDSS and BICAMS scoring SSA uses as a severity proxy, the disease-modifying therapy record, and the two backup paths if you fall short at Step 3. We close with two worked Massachusetts and Florida cases that show how the file is built.

If you are filing or appealing an MS claim, the goal is a file that tells SSA, line by line, how your MS reaches one of the two 11.09 endpoints. See If You Qualify.

What 11.09 Actually Says

Here is the verbatim text of Listing 11.09 from the SSA Blue Book Section 11.00 Neurological (Adult):

That is the whole listing. Two paragraphs. Two different roads to approval. Most MS claimants who win at Step 3 do so under Paragraph B, because the cognitive and fatigue burden of MS often shows up before walking ability deteriorates enough to satisfy Paragraph A.

Paragraph A: Disorganization of Motor Function in Two Extremities

Paragraph A wants the file to show two things working together. First, disorganization of motor function in two extremities under 11.00D1. Second, that disorganization producing an extreme limitation in one of three specific motor abilities under 11.00D2. Both parts have to be in the record.

11.00D1: What Two Extremities Means

SSA defines disorganization of motor function as interference with movement of two extremities caused by your neurological disorder. Two extremities can be both lower extremities, both upper extremities, or one upper and one lower extremity. The two-extremity rule is not a half-body rule. A claimant with right-leg foot drop and left-arm intention tremor satisfies the two-extremity threshold the same way a claimant with bilateral spastic legs does.

The interference has to come from your MS. Pre-existing knee arthritis or carpal tunnel does not count. The file needs neurology notes that tie the motor dysfunction to demyelination, lesion location on MRI, or relapse history.

11.00D2: What Extreme Limitation Means

This is where most Paragraph A claims live or die. Extreme limitation has three SSA-defined endpoints, and the file needs to hit one of them:

1. Inability to stand up from a seated position. SSA means you cannot stand and maintain an upright position without assistance from another person or an assistive device such as a walker, two crutches, or two canes.
2. Inability to maintain balance in a standing position. SSA means you cannot maintain an upright position while standing or walking without assistance from another person or an assistive device such as a walker, two crutches, or two canes.
3. Inability to use your upper extremities. SSA means loss of function of both upper extremities that very seriously limits the ability to independently initiate, sustain, and complete work-related activities involving fine and gross motor movements. Examples include not being able to pinch or use fingers; not being able to handle, grip, grasp, hold, turn, or reach; or not being able to lift, carry, push, or pull.

A single cane is not enough. A unilateral lower-extremity AFO brace is not enough. SSA wants bilateral assistance documented across multiple visits over at least 12 months. If the medical source statement reads "patient uses a cane intermittently for community ambulation," that is a Step 5 RFC argument, not a Step 3 11.09A win.

Paragraph B: Marked Physical Plus Marked Mental

Paragraph B is the path most well-built MS files take. It requires marked limitation in physical functioning under 11.00G3a AND marked limitation in one of four mental functioning areas under 11.00G3b. Two markeds, not one, but the physical marked and the mental marked are different in kind, which spreads the proof across the file.

11.00G2: What Marked Limitation Means

SSA explains that "marked" sits as the fourth point on a five-point scale: none, mild, moderate, marked, extreme. You do not have to be confined to bed, hospitalized, or living in a nursing home to be marked. SSA looks at the nature and overall degree of interference with your functioning. Marked means you are seriously limited in the ability to independently initiate, sustain, and complete work-related activities on a sustained basis.

11.00G3a: Marked Physical Functioning

Marked physical functioning means MS-driven symptoms that seriously limit your ability to stand, balance, walk, use both upper extremities for fine and gross movements, or some combination involving one upper and one lower extremity. SSA also accepts marked physical limitation from MS-related vision problems (uncorrectable double vision affecting balance), breathing limitations (needing a CPAP), aspiration, or pain and fatigue that medical records document as persistent and serious.

Fatigue is huge in MS files and SSA explicitly recognizes it under 11.00T. The Fatigue Severity Scale (FSS) above 36 and the Modified Fatigue Impact Scale (MFIS) above 38 are recognized in the MS literature as clinically significant. SSA does not require those exact numbers, but treating providers using them in chart notes give SSA a quantitative anchor.

11.00G3b: Marked Mental Functioning, Pick One

You only need marked in ONE of the four mental areas to satisfy Paragraph B. The four areas are the same four used in Section 12 mental listings, which is helpful because cognitive testing in MS maps cleanly to them.

1. Understanding, remembering, or applying information. Learning terms and instructions, following one- or two-step oral instructions, describing work activity, asking and answering questions, recognizing and correcting mistakes, identifying and solving problems, sequencing multi-step activities, and using reason and judgment to make work-related decisions. MS cognitive testing flags this through SDMT processing speed and CVLT-II verbal memory.
2. Interacting with others. Cooperating, asking for help, handling conflicts, stating a point of view, initiating or sustaining conversation, understanding social cues, responding to requests and criticism, and keeping interactions free of excessive irritability or argumentativeness. MS often hits this area through pseudobulbar affect, depression, and anxiety. PBA is well-documented in MS (Center for Neurologic Study-Lability Scale score above 13 is the screening threshold).
3. Concentrating, persisting, or maintaining pace. Working at consistent pace, completing tasks in timely manner, ignoring distractions, sustaining ordinary routine and regular attendance, and working a full day without needing extra rest periods. This is the most common 11.00G3b area MS claimants win on because MS-related cognitive fatigue and processing speed deficits land here. The SDMT is the gold-standard cognitive measure for MS and it specifically tests processing speed.
4. Adapting or managing oneself. Responding to demands, adapting to changes, managing psychologically based symptoms, distinguishing acceptable and unacceptable work performance, setting realistic goals, maintaining personal hygiene and attire appropriate to a work setting, and being aware of normal hazards.

McDonald 2024 Diagnostic Criteria and What Goes in the File

SSA does not require a specific MS diagnostic schema, but the 2024 revision of the McDonald criteria (Thompson, Banwell, Barkhof et al., 2024 update following the 2017 framework) is the consensus standard. Your DDS examiner expects to see it in the neurology notes. The 2024 update added optic nerve as a fifth qualifying anatomical location for dissemination in space, broadened the role of central vein sign and paramagnetic rim lesions in MRI, and tightened the kappa free light chain index threshold.

Dissemination in space and dissemination in time are the two diagnostic anchors. The file should contain:

• MRI brain with and without gadolinium showing T2 hyperintense lesions in at least two of five MS-typical regions: periventricular, juxtacortical or cortical, infratentorial, spinal cord, and the optic nerve (added in 2024). The Barkhof criteria require at least 9 T2 lesions or 1 gadolinium-enhancing lesion plus 3 T2 lesions, plus involvement of typical regions.
• MRI cervical and thoracic spine with sagittal STIR and T2 sequences for spinal cord lesions.
• Cerebrospinal fluid analysis showing oligoclonal bands present in CSF and absent in serum (positive in 95 percent of MS), elevated IgG index above 0.7, and kappa free light chain index above the lab threshold (the 2024 criteria added KFLC as an alternative to OCB).
• Visual evoked potentials showing prolonged P100 latency where optic neuritis is part of the history.
• Optical coherence tomography with retinal nerve fiber layer thinning where optic neuritis has occurred.
• Relapse history with dates, neurologist confirmation, MRI evidence of new lesions during relapses, and steroid taper records.

EDSS and BICAMS: How SSA Reads Severity

The Expanded Disability Status Scale (EDSS) is the standard physical disability measure in MS. It runs from 0 (normal) to 10 (death due to MS) in half-point increments. EDSS scores correlate with 11.09 outcomes:

The Brief International Cognitive Assessment for MS (BICAMS) is the consensus MS cognitive battery and SSA examiners increasingly look for it. BICAMS has three tests:

• Symbol Digit Modalities Test (SDMT). Processing speed. Z scores below -1.5 are clinically impaired. Below -2.0 maps to marked CPP under 11.00G3b(iii).
• California Verbal Learning Test, Second Edition (CVLT-II), Trial 1-5 Total Recall. Verbal learning and memory. Below -1.5 maps to marked URA under 11.00G3b(i).
• Brief Visuospatial Memory Test, Revised (BVMT-R), Total Recall. Visuospatial memory.

The full Minimal Assessment of Cognitive Function in MS (MACFIMS) adds the PASAT, Judgment of Line Orientation, COWAT, Delis-Kaplan EF subtests, and California Verbal Learning Test-II Long Delay. If your MS team did a full MACFIMS, that report carries serious weight at hearing.

Timed Functional Tests SSA Reads as Physical Severity Anchors

• Timed 25-Foot Walk (T25-FW). Average of two trials. Above 8 seconds correlates with EDSS 6.0+. Doubling of baseline is a recognized progression marker.
• Nine-Hole Peg Test (9HPT). Times above 25 seconds per hand are clinically impaired. Above 40 seconds maps to inability to do sustained fine motor work.
• Six-Minute Walk Test. Distances under 300 meters at 6 minutes correlate with marked physical limitation under 11.00G3a.
• MS Functional Composite (MSFC). Z-transformed combination of T25-FW, 9HPT, and PASAT. Worsening Z score across the year is direct progression evidence.

The 2025 to 2026 Disease-Modifying Therapy Picture

The DMT record is not just about MS care quality. It is severity proof. If the file shows DMT escalation across three or more agents, plus continued relapses or progression, SSA reads that as evidence the underlying MS is aggressive and treatment-refractory. Here is the active 2026 DMT picture:

Anti-CD20 Monoclonals (High Efficacy)

• Ocrelizumab (Ocrevus). IV every six months. Approved for RRMS and PPMS. The PPMS approval makes Ocrevus the cornerstone PPMS therapy.
• Ocrevus Zunovo. Subcutaneous formulation approved September 2024. 10-minute injection every six months. Same active ingredient, easier delivery.
• Ofatumumab (Kesimpta). Subcutaneous monthly. Self-administered. Anti-CD20 with rapid onset.
• Ublituximab (Briumvi). IV every six months after loading. Approved December 2022. Glycoengineered anti-CD20 with faster infusion time.

S1P Receptor Modulators (Oral, High Efficacy)

• Fingolimod (Gilenya). Daily oral. First-in-class. Requires baseline cardiac monitoring at first dose.
• Siponimod (Mayzent). Daily oral. Approved for active SPMS. Requires CYP2C9 genotyping before starting.
• Ozanimod (Zeposia). Daily oral. Selective S1P1 and S1P5.
• Ponesimod (Ponvory). Daily oral. Selective S1P1.

Other High-Efficacy Agents

• Natalizumab (Tysabri). IV monthly. JC virus antibody monitoring required due to PML risk. Sub-Q formulation Tyruko approved 2023 as a biosimilar.
• Alemtuzumab (Lemtrada). IV induction therapy. Two annual courses. Requires REMS monitoring for 48 months due to autoimmune secondary effects.
• Cladribine (Mavenclad). Oral pulse therapy. Two annual courses then often holiday.

Moderate Efficacy Oral DMTs

• Dimethyl fumarate (Tecfidera) / Diroximel fumarate (Vumerity) / Monomethyl fumarate (Bafiertam). The fumarate family.
• Teriflunomide (Aubagio). Daily oral. Pyrimidine synthesis inhibitor.

Older Injectables

• Beta interferons. Avonex, Rebif, Betaseron, Extavia, and Plegridy. Largely displaced by oral and monoclonal therapies but still in use.
• Glatiramer acetate. Copaxone and Glatopa. Subcutaneous.

Newer 2025 Pipeline

• Tolebrutinib. BTK inhibitor. The HERCULES trial in non-relapsing SPMS read out in 2024 showing reduction in confirmed disability progression. FDA review ongoing through 2026.
• Vidofludimus calcium (IMU-838). Phase 3 CALLIPER for PPMS.
• Frexalimab (CD40L inhibitor). Phase 3 trials active 2025-2026.

Symptomatic and Acute Treatment

Relapse treatment is high-dose IV methylprednisolone 1g for three to five days, often followed by an oral prednisone taper. Plasmapheresis is reserved for steroid-refractory severe relapses. Symptomatic agents in the chart commonly include dalfampridine (Ampyra) for walking speed, baclofen and tizanidine for spasticity, gabapentin and pregabalin for paresthesias, modafinil and amantadine for fatigue, dextromethorphan-quinidine (Nuedexta) for pseudobulbar affect, oxybutynin and mirabegron for neurogenic bladder, and SSRIs for comorbid depression.

Autologous hematopoietic stem cell transplant (HSCT) is used at major MS centers for highly active relapsing MS that has failed at least one high-efficacy DMT. The BEAT-MS trial comparing HSCT to best available DMT is enrolling through 2026. If your file shows HSCT, that is unambiguous evidence of severe, treatment-refractory MS.

The Two Backup Paths If 11.09 Falls Short

Medical Equivalence Under SSR 17-2p

SSR 17-2p lets a claim satisfy a listing through medical equivalence rather than meeting it on the literal text. For MS, common equivalence arguments include severe MS optic neuritis equivalence to Listing 2.02 statutory blindness, neurogenic bowel and bladder equivalence to Listings 5.06 (IBD) or 6.06 (genitourinary), and combined cardiac involvement from MS-related dysautonomia equivalence to 4.05 recurrent arrhythmias. An equivalence finding at the DDS level requires a Medical Consultant signoff (form SSA-2506-BK or its electronic equivalent), and at the hearing level requires a Medical Expert opinion. The ALJ cannot find equivalence without an ME on the record. Always request an ME at the prehearing conference if your file is leaning on equivalence.

Step 5 RFC Erosion Under SSR 96-9p and SSR 85-15

If neither 11.09A nor 11.09B is met, the claim continues to Step 4 and Step 5. SSR 96-9p governs erosion of the sedentary occupational base. SSR 85-15 governs nonexertional limitations. MS commonly erodes the sedentary base through:

• Less than occasional fingering or handling, which alone takes more than 50 percent of unskilled sedentary jobs off the table.
• Unscheduled rest breaks more than two times daily of 10+ minutes each due to fatigue. This is a job-ending limit.
• Off-task time above 10 percent due to cognitive symptoms.
• Absences above one per month due to relapses or DMT infusion days.
• Heat intolerance (Uhthoff phenomenon) limiting tolerable workplace temperature.
• Use of a cane or walker for ambulation, limiting unprotected heights and moving machinery.

The vocational expert testimony at hearing should be cross-examined with each of these RFC limits. Two days of unscheduled absence per month eliminates competitive employment under most VE testimony. The 5-day rule under 20 CFR 404.935 requires submission of all evidence at least five business days before the hearing, including any updated medical source statement from your neurologist.

The HA-1152 Medical Source Statement Counterweight

The HA-1152 Medical Source Statement (or the MSS supplied by your attorney) is the most powerful single document in a Step 3 or Step 5 MS file. The neurologist should fill it out with specific 11.00D and 11.00G language. The strongest MSS includes:

• Diagnosis with McDonald 2024 criteria met, MS subtype (RRMS, SPMS, PPMS, CIS), date of onset.
• Current EDSS score with date.
• T25-FW time and 9HPT times.
• Most recent MRI brain and spine findings with lesion count and gadolinium status.
• Current DMT and all prior DMTs, with reasons for switching.
• Relapse log for the past 24 months with date, symptoms, and treatment.
• Specific functional limits keyed to 11.00G3a (physical) and 11.00G3b(i-iv) (mental areas).
• BICAMS or MACFIMS results, if available.
• Statement on fatigue with FSS or MFIS score.
• Statement on heat sensitivity and Uhthoff phenomenon.
• Off-task time estimate, absence per month estimate, and break frequency.

Under 20 CFR 404.1520c, treating-source opinions are no longer entitled to controlling weight, but supportability and consistency are the two persuasiveness factors that get top priority. The MSS that ties each limitation back to a specific exam finding, MRI lesion, or cognitive test score wins on both factors.

Worked Example: Linda 44 Worcester MA RRMS Transitioning to SPMS

Worked Example: Robert 51 Tampa FL Primary Progressive MS

How to Build a Winning 11.09 File

1. Get the MRI and CSF in the file. Brain MRI with gadolinium, cervical and thoracic spine MRI, CSF with OCB and IgG index (and KFLC if available). Without these, the examiner cannot tie limitations back to MS.
2. Document the DMT history. Every DMT, every switch, every reason for switching. DMT escalation is severity proof.
3. Get current EDSS and timed functional tests. T25-FW, 9HPT, six-minute walk. Update at least every six months.
4. Get BICAMS or full MACFIMS. SDMT, CVLT-II, BVMT-R at minimum. Without cognitive testing, Paragraph B marked mental is hard to prove.
5. Document the relapse log. Dates, symptoms, steroid courses. A claimant who has had four relapses in 18 months has a different file from one in stable remission for three years.
6. Document fatigue and heat sensitivity. FSS, MFIS, neurologist statement on Uhthoff phenomenon. These are not optional add-ons. They are core 11.00T and RFC fuel.
7. Document assistive device use across multiple visits. For 11.09A, the devices have to be bilateral and used for at least 12 months. PT and OT notes carry more weight than self-report.
8. Get the HA-1152 MSS done by your treating neurologist. Specific to 11.00D2 and 11.00G3a-b. Quantitative limits. Off-task percent, absence per month, break frequency.

Where Each Claim Type Fits Within Section 11 and Beyond

MS is the heart of 11.09, but the listing also catches a few overlapping presentations. Neuromyelitis optica spectrum disorder (NMOSD, anti-aquaporin-4 positive) and MOG antibody disease (MOGAD) are not MS but they often show up in 11.09 files because of overlapping symptoms. NMOSD has its own FDA-approved therapies (eculizumab Soliris, satralizumab Enspryng, inebilizumab Uplizna), and SSA usually evaluates them under medical equivalence to 11.09 or 2.02 if optic involvement dominates. The 2025-2026 NMOSD treatment standard now includes ravulizumab (Ultomiris) per the CHAMPION-NMOSD trial.

For pure cognitive presentations without significant motor involvement, see our breakdown on Listing 12.02 neurocognitive disorders if the cognitive testing shows major NCD-level deficits. Where MS is one piece of a multi-system file, see the related deep dives on Listing 1.15 spinal nerve root compromise and Listing 11.14 peripheral neuropathy. If your MS is paired with severe depression or anxiety, look at Listing 12.04 depressive disorders and Listing 12.06 anxiety and OCD. State-specific filing guides for MA, FL, CA, TX, NY, and PA are at Massachusetts, Florida, California, Texas, New York, and Pennsylvania.

Frequently Asked Questions