This link offers a fairly clear description of the requirements involved in the MS/Social Security Disability determination.  (The link is to a law firm's website and although I believe the information to be correct, the source has not been "vetted" by me.)

For your reference as necessary; This page lists and explains various terms and abbreviations. (Local page)

Definition of disability with regard to the Social Security Administration.

Two different types of disability support available from the federal government.

Can I receive both SSDI and SSI payments?

Can I work and still receive benefits while on SSDI or while on SSI?

How much money will the government give me in SSDI or how much in SSI?

Will receiving benefits effect my retirement?

The 5 Steps of a Social Security Disability Case

Will I qualify?

I have so many complicated and varied problems, how can I even explain my situation?

Where do my symptoms fit into the SSA's categories?  (find my specific symptoms appropriately  referenced here and noted in red text)(Local page)

Exertional and Non-Exertional Limitations

About the Doctor's Residual Functional Capacity Form (RFC ) (includes a link for an optional RFC form) - OR - Print the original government provided RFC form here

What is the Compassionate Allowance List?  Click here to view the actual list.  The rare condition Malignant Multiple Sclerosis is on the list, but the other more common forms of MS are not.

What information will I need?: Medical information

How long will this process take?

An attorney is not a legal requirement to apply for SSDI or SSI Benefits.  But, will obtaining an attorney be in my best interest?

How much will an attorney cost?

Should I collect all my  information before applying or just submit the contact information to SSA and let them request it from the doctors?

This page lists many SSA frequently accessed codes and listings with regard to MS. (Local page)

My personal challenges (Local page)

Very important!            (Establish a Protective Filing Date)           Start the process asap.

There are no commitments or decisions necessary now.  It's just like getting in line while you're deciding your next move, or maybe deciding on no move at all. But it's important to get in line now. Establishing a protective filing date may effect the dollar amount of any future benefits you may be awarded.  Follow the link above to learn more.  You can always just not complete the process if you choose not to file,  no harm / no foul, but that decision can be made later.  Just establish a filing date now in case you do choose to file.