I have a basic question. Does a Form 990 or some other form need to be filed for a section 457 trust for a governmental plan?

No Form 990 is required for any "state institution whose income is excluded from gross income under section 115." Instructions to the Form 990. (The Acrobat Reader is necessary to read the instructions online, but you can download it for free by clicking here.) And governmental pension plans are exempt from Form 5500 requirements; you can click here to see the relevant IRS notice. So there should not be any filing requirements, other than the normal ones with respect to distributions and the like.

Elena and Carol, would be interesting to know which STATES require trust fund reporting. California has an existing requirement for governmental retirement plans that entails filing a report with the State Controller, also requires an audit, and if a DB, an actuarial report to be included. Still up for grabs: Will 457 plans be covered--likely answer is YES.