If I remember correctly, there are ERISA rules surrounding how many days an employer has to respond to a participant's request for a benefit calculation, an SPD, or a plan document.

Can anyone point me to where I could find the details on these timing requirements?

Susan--ERISA 502©(1) provides that a plan administrator has 30 days to respond to a participant's request for any information that ERISA requires the administrator to provide on request (e.g., an SPD).

Though you have an enforceable right to only get one benefit calculation each year, I think.

Make sure the request is directed to the "plan administrator," who is named in the SPD. Oughta be in writing.

(Makes for a delicious catch-22 if you don't have the SPD yet, yes?)

Dave is correct. In fact, I think the procedure for doing just what you ask is supposed to be outlined (briefly, not detailed) in the SPD, including the address.