Very likely legitimate. A rate that low almost always means an assumable government-backed loan, probably VA, possibly FHA. In an ordinary arms-length sale, a conventional loan's due-on-sale clause keeps a buyer from taking over the rate (conventional assumptions do happen, but in specific transfers like divorce or inheritance, with the servicer's approval). Government loans, FHA, VA, and USDA, are assumable by a buyer who qualifies with the servicer. So a seller advertising a transferable 1.9% is almost certainly sitting on FHA or VA financing from a low-rate stretch. Between the two, we would lean heavily toward VA. FHA streamline refinances run through a maximum-mortgage calculation that makes it hard to push a rate into the very low twos without the borrower buying it down with points, while VA has no equivalent restriction, so VA is where the truly rock-bottom assumable rates usually live. A shorter 15-year FHA term could get there, but VA is the safer bet. The catch that trips buyers up is equity. You assume the balance at its rate, but you still owe the seller for everything the home is worth above that balance. As an illustration, if a home sells for around a million dollars and the assumable balance is about half that, the buyer brings roughly half a million in cash or separate financing to close, fantastic rate or not. The lower the rate, the older the loan, and often the larger that equity gap has grown. So the rate can be entirely real and still out of reach without significant cash. If you are eyeing a specific assumable listing, we can help you figure the cash-to-close before you fall in love with the rate.