Is salary negotiable in this situation?

I recently got a job offer for a position with my state's Dept. of Health. They sent me some forms to fill out prior to my interview a few months ago. One of these forms was a 'salary demand form', which just had a statement "The lowest salary that I would be willing to accept for X position would be _____." The State has a standard salary schedule w/ base salaries and step increases dependent on grade.

How would I go about negotiating a higher salary than the amount I already filled out on this form? I'm not sure if the negotiating process is any different with a state job since they have a set salary schedule?

usa jobs
usa jobs resume
usa hotel jobs
usajobs
usa jobs federal government
usa job in ksa
usa jobs
usa jobs login
usa jobs gov
usajobs.gov
www.usajobs.gov
usajobs.com
usajobs
usajobs.gov official