In 2025, the Phan brothers' grandmother was admitted to Memorial Hermann in Houston. She came home with a $751,000 hospital bill — sixty-six pages of itemized charges, five separate admissions, and the kind of medical-billing language that makes most families file the envelope and hope for the best.

Ian, 15, and Grayson, 14, sat down with the bill at the kitchen table and started reading. They found the CMS Physician Fee Schedule. They found the Clinical Laboratory Fee Schedule. They found the NCCI bundling rules. Then they started checking — line by line — what the hospital had charged against what Medicare actually pays.

Six weeks later, they had $323,000 in flagged overcharges, a stack of dispute letters, and a growing conviction that what they had just done by hand should be doable for any patient in minutes. So they started building.

BillXM is what came out of that work. The same checks they ran on their grandmother's bill — same data sources, same dispute templates — packaged into a tool that anyone with an emergency-room statement and three minutes can use.