Here is a link from Mass CFIDS on the new determination letter from SS:
https://www.masscfids.org/resource-...fsme-social-security-disability-claimsreviews
The determination letter has the "rules" that your judge will look at. So try to provide evidence for all of the rules that you can. Your lawyer should be familiar with this letter.
The abnormal labs and tests and a doctor's diagnosis will show that you have CFS. I had a few tests like a high EBV titer and abnormal thyroid as well as my doctor's diagnosis.
BUT what they really want to know is, can you work full time 40 hours a week 52 hours a year? In theory, you could have no diagnosis at all and still get approved as long as you can prove you can't work.
Have your doc write a letter saying that you not only have CFS, but that you're unable to work.
Then get some testing to prove you can't work:
For this you need a Functional Capacity Evaluation (FCE). This will show how fatigue and pain affect your ability to work. You can provide your own testing or SS may send you to one if you didn't provide one and can't afford one. Talk to your lawyer about that.
You can also do a Neuropsych test which shows how cognitive dysfunction affects your ability to work. Again you can provide your own or SS might send you to one. It can also pick up on anxiety or depression. This is fine as long as you're not applying for Long Term Disability through your employer.
I had both the FCE and Neuropsych tests done. Luckily, I still had medical insurance, so my insurance paid for that.
Then you also want to provide a record of continuing disability. You do this going to see your doc every three months while you're waiting for your hearing. Have your doc document that you continue to be disabled. My lawyer had a nifty form for my doc to fill out for this purpose.
My judge liked this last evidence the best. I was able to be approved "on the record" without having to go to a hearing.