Aggregating median HH income and calculating MOEs

I am attempting to aggregate the median household value for a set of tracts using the 2014-2018 ACS 5-year.  The base data is from table B19013, which reports the median household values in dollars for each census tract.  

I'm doing my analysis in R.

What is the accepted methodology for aggregating median values?  How should one calculate the MOEs for this aggregated medians?

I found this reference for re-calculating a median, but it is based on the range of household values:

http://www.dof.ca.gov/Forecasting/Demographics/Census_Data_Center_Network/documents/How_to_Recalculate_a_Median.pdf

Is there an approach to aggregating the median using the median values?

I'll post the code once I find a solution.

Thanks

Adam B.