What determines how long an induvidual can be gone for Jury Duty. At what point and to what degree does an employer have the right to fill a vacant position due to extended jury duty.

It is my understanding that Jury Duty is like Military Service. Even if you fill the vacant position the employee has the right to return to work even if you have filled the position.

You do not have to pay an employee for Jury Duty. That is a decision of the employer - usually covered in the Employee Handbook.

But you cannot terminate or refuse to allow an employee back to work solely on the basis of jury duty.

Rights of employees relative to jury duty is a matter of state, not federal law. It ranges from the mere obligation to not reprimand the employee for accepting the duty and keeping some job open to continued pay from employer for the time serving on the jury with some limit as to the number of days.

BNA has a good service that covers these rules by state, also Panel Publishers has a paperback book on Mandated Benefits.