The Department of Government Efficiency started as an inside joke. It’s since enabled the world’s richest man to become the most powerful person in the country, after President Donald Trump. And yet the department-that’s-not-a-department remains something of an enigma.

Over the years, Musk and his businesses have received at least $38 billion in government contracts, loans, subsidies and tax credits, often at critical moments, a Washington Post analysis has found, helping seed the growth that has made him the world’s richest person.