That all depends on who makes the holster and what it is made of. While some holsters are made to accommodate many weapons some are made exclusively for a particular, especially a Black Hawk or Fobus so the best thing to do is take your holsters to a gun store that has an M&P 40 and see if it actually fits well and is satisfactory for you, I my self would purchase one expressly for my new weapon, but that is my opinion since I favor Black Hawk serpa holsters!