Below are OPM's stated criteria for winning FERS Disability Retirement Cases. Now, what does this gobbledygook mean? There are thousands of cases defining what these criteria mean, and new cases redefine the criteria all the time. Thus, these criteria are anything but straightforward. The ultimate point here is that you need someone with a knowledge of the case law which interprets these criteria, knowledge which you likely don't have, but a good lawyer should have.

OPM's Seven Criteria:

Required Documentation

To decide if your disability claim is allowable, OPM considers the documentary evidence you, your agency, and your physician provide. Your claim can be allowed only if the evidence establishes that you meet all of the following criteria:

1. A deficiency in service with respect to performance, conduct or attendance, or, in the absence of any actual service deficiency, a showing that your medical condition is incompatible with other useful service or retention in the position.
2. A medical condition, which is defined as a health impairment resulting from a disease or injury, including a psychiatric disease.
3. A relationship between the service deficiency and the medical condition such that the medical condition has caused the service deficiency.
4. The disability must be expected to last at least one year.
5. You became disabled while serving under the Federal Employees Retirement System.
6. The inability of your employing agency to make reasonable accommodation to your medical condition.
7. The absence of another available position, within the employing agency and commuting area, at the same grade or pay level and tenure, for which you are qualified for reassignment. OPM will not pay for any medical examination or procedure needed to provide the necessary documentation.