@CHAS25 can you please be more specific and detailed on why you believe you are right and the TSP administrator is wrong? what is your current circumstance? Married? widowed? etc.
when is this joint and survivorship table appropriately used per IRS rules? can you please explain?
see this link. I see nothing stating that the Joint and Survivorship table is to be used to determined RMD.
https://www.tsp.gov/publications/tspbk26.pdf
