Costco is now the highest-volume hearing aid retailer in the country — approximately 16 percent of the U.S. market in 2026 according to industry trackers. That is not an incremental achievement. It is a commercial transformation of the hearing healthcare market — one that has happened almost entirely on the strength of a single institutional value proposition: the same premium hearing technology available at private audiology practices, at prices that are 50 to 75 percent low