Here is something that the California State Data Center shared with the SDC listserv.  I have permission from Nancy to share with CTPP!

Elaine

Subject: ACS Median Calculator

We thought we would share our article on calculating a median from aggregated range data and the Excel calculator.  This example uses household income but the concepts could be used for any range data.    The formula for calculating the MOE comes from the ACS PUMS Accuracy statement which would also be the source for the Design factor which you should check for your state or any other variable. 

Nancy Gemignani

California State Data Center

Demographic Research Unit

(916) 327-0103 ext 2550