The "20% down" rule isn't a law — it's a holdover from an older era of lending. Twenty percent down lets you skip private mortgage insurance (PMI) on a Conventional loan, which is a real benefit. But somewhere along the way, that benefit got rebranded as a requirement, and it stuck.
Today, more than half of first-time homebuyers put down less than 10%. Many put down 3%–5%. Some put down zero. The real question isn't "do I have 20%?" — it's "what makes sense for my situation?"