80% of medical bills contain at least one error — duplicate charges, upcoding, phantom services. Most people just pay. BillGuard AI analyzes your bill and flags suspicious charges with plain-English explanations. Then writes a professional dispute letter ready to send. Free to analyze. $9.99 for the dispute letter. Human advocates charge 20–35% of savings — on a $5,000 bill that's up to $1,750. No account needed. Takes 60 seconds.