1. This is the second part of a two-part article. The first appeared in the February 2020 issue of Health Affairs. It is part of a series on transforming health systems published with support from The Robert Wood Johnson Foundation. This is an open access article distributed in accordance with the terms of the Creative Commons Attribution (CC BY 4.0) license, which permits others to distribute, remix, adapt, and build upon this work, for commercial use, provided the original work is properly cited. See ....