Both Desantis and Galco make leather speed scabbards and thumb break models for this gun series. I have several different types for different situations.
What kind of holster are you looking for exactly...pancake, SOB, paddle, IWB, minimalist, shoulder....?
I am a huge M&P fan and carry the 9L as my primary in a Desantis pancake speed scabbard. I have found that Glock 21 holsters fit the M&P series very well also, and commonly use a Galco minimalist speed scabbard made for the Glock 21 for both my 9L and 9c. For some reason, the Glock 21 holsters fit A LOT of guns.
The entire line of M&Ps will of course be able to share the same holster.
Send me a PM if ya wana talk S&W M&P.