"Before, I was thinking that the wash sale was rolled into the cost basis of the next shares you purchased, which would be the next month"
If you make monthly purchases, you can trigger a wash sale be redeeming.
It is the earliest purchase within the +/- 30 day window that is adjusted first. i.e. likely the previous or current month.
You will be getting the benefit of your adjusted basis sooner or later, probably later assuming First in First out reporting.
