"To Reassign or Not to Reassign"

Under the Americans with Disabilities Act of 1990, is an employer mandated to reassign a qualified disabled employee to a vacant position, contrary to the employer's own implemented policy of hiring the best candidate for the position? The circuit courts are split on this question, with the Tenth and the DC Circuits requiring mandatory reassignment of a disabled employee and the Eighth and the Seventh Circuits allowing for an exception to the employer's reassignment duty if the employer has an actual policy and practice of hiring the most qualified candidate for open positions.