White started his career as a consultant at McKinsey & Co.. He joined Abbott in 1984, serving there in management positions including Senior Vice President of Diagnostic Operations and Executive Vice President. He was elected to the board of directors in April 1998, to chief executive officer in 1998, and to chairman of the board in April 1999. As of November 2019, White's tenure is the second longest for a non-founder CEO among the S&P 100. Under his leadership, he has created approximately $200 billion in shareholder value.