Warren’s financing plan has two parts. The first describes her approach to estimating the costs of Medicare-for-all. The second lays out the way she pays for the plan without, in her words, “one penny” of middle-class tax increases.As befits Warren’s wonkish, master-of-plans persona, she’s relied in both cases on top experts. Her cost estimate was conducted by Don Berwick, the former director of the Centers for Medicare and Medicaid Services; and Simon Johnson, the former chief economist at the World Bank. Her tax plan was developed by Betsey Stevenson, who served as chief economist at the Labor Department; Mark Zandi, the head economist at Moody’s Analytics; and Johnson. Helpfully, her plan is backed up by two detailed appendices laying bare, and arguing for, the assumptions Warren makes.