How to join point and polygon layers but retain polygon geometry for choropleth in ArcMap?

background: I tried to join a point layer and a polygon layer so that I could make a choropleth map of the attributes in the point layer but all I can get is a point map regardless of which layer I choose to initiate the join

use case: I wish to map rates of heart attack within by zip code normalized to population and symbolize with three quantiles in a choropleth map

things I tried: googled this question, read Kurland and Gorr GIS tutorial for health 5th ed

I'm using ArcMap 10.3.