Does an employer have to fill out a new 5305 each time the form is updated by the IRS or can the employer continue to use the original form assuming nothing has changed with regard to eligibity?

It depends. If the March 2002 version of Form 5305A-SEP is being used, the June 2006 version does not need to be adopted. The December 2004 version of Form 5305-SEP was not required to be adopted if the employer was using the March 2002 version (which had to be amended by December 31, 2002).

[The compensations are automatically increased to the current years limits.]

Hope this helps (and you don't need need information for an earlier year's form).

What do we do with a really old 5305-SEP? Back in the day, the forms 5305-SEP had expiration dates on them. This changed in 1997. My concern is that a sponsor of a 5305-SEP that hasn't updated since the "expired" version has been operating the plan for the last 10 years without a plan document. Anyone have any experience with this?