When I bought my house in October 2013, I had the water tested. Iron was .73mg/L which was over the .3 mg/L DEP/EPA standard. Previous tests (in 2012) and follow up tests after 2013 reported lower levels of iron in the .1-.2 range. I can't explain why that is but the point is, conditions of a well can change.
There are two difference types of iron - ferrous (can't see) and ferric (can see). A water softener can remove ferrous iron via the ion exchange process. However, they cannot remove ferric iron. A separate filter, or a combination softener/filter, is needed to remove ferric iron. The filter media that is used to filter iron and other materials greatly varies so do your homework. Terrylove.com forums was a helpful source of info for me.
I ended up going with a Marlo CMP-25 combo unit. Although I probably did not NEED the media filter, I decided that it was worth the extra investment and piece of mind in case conditions changed in my water.