Joyner earned a Bachelor of Business Administration in finance from Texas Tech University in 1986.
[1] In October 2024, Joyner became the president and chief executive officer of CVS Health, along with joining the board of directors.
[10] Reuters reported that Joyner was appointed after pressure from investors over low company share price.
[7] In July 2024, he testified before the United States House Committee on Oversight and Accountability about pharmacy benefit managers and prescription drug markets.
[11] Representative James Comer (R–KY) threatened him and "leaders of the [other] three largest pharmacy benefit managers in the country with steep fines – or jail time – for allegedly lying in a recent congressional hearing.