The Smith & Wesson M&P9 line is not one gun, it’s a family, and an inside-the-waistband holster has to be molded to the specific member of that family you own. The current M2.0 lineup runs a 4″ barrel Compact, a 4.25″ Compact, and a 4.6″ full-size, alongside a Performance Center Metal Spec Series with a threaded 4.8″ barrel and a built-in compensator. A holster cut for one will not properly retain another — the difference in slide length and dust-cover shape is enough to change how deep the gun sits and where the trigger guard lands relative to the holster’s retention ledge.
Fit specifics: OR cuts, lights, and the M2.0 texture change
Two details trip people up when buying separately from the gun. First, the M2.0 OR (Optics Ready) models need an optic-cut holster — a standard holster mouth can crush a mounted red dot or simply refuse to seat the slide fully, which throws off retention on everything below the optic. Buy the optic cut even if you haven’t mounted a dot yet; it fits an unmounted slide fine and saves a second purchase later. Second, if you run a weapon light (a TLR-series light is the common pairing), that needs its own holster molded around the light and gun together — a bare-gun holster won’t accommodate the added bulk at the dust cover, and forcing it in wears the light’s finish and can affect retention. Also worth knowing: the M2.0 changed grip texture and shaved dimensions slightly from the original M&P, so a holster listed only for “M&P9” without the M2.0 designation may be for the older gun.
Retention: what “Level” actually means
Retention ratings aren’t marketing fluff, they describe a specific mechanism. Level I is passive friction retention — the holster’s molded shape grips the gun with no moving parts, which is what nearly every concealment IWB holster uses. Level II adds an active retention device on top of that, usually a thumb-activated hood or strap the wearer must release before the gun clears the holster; this is standard on duty holsters, rare on concealment ones. Level III stacks a second independent lock, typically a rotational or trigger-guard-engaging mechanism, aimed at preventing a gun grab in a struggle — overkill for concealed carry, standard for uniformed duty use. For an M&P9 carried IWB, Level I passive retention is what you want; the goal is a fast draw for yourself, not resistance to a takeaway attempt.
Material trade-offs, in depth
Kydex is a rigid thermoplastic, vacuum-formed around the actual gun. It holds its molded shape indefinitely, doesn’t absorb sweat or humidity, and almost every Kydex holster has an adjustable retention screw so you can tighten the fit as the holster’s tiny working parts wear in. Its one real downside is that a too-tight or poorly broken-in Kydex holster can leave holster-wear marks on a gun’s finish over months of daily draws. Leather is the opposite trade-off: it molds to your body and the gun’s shape through wear and, on quality holsters, deliberate wet-forming, and it’s softer against bare skin for all-day IWB carry. But leather absorbs sweat, which can promote surface rust on a carbon-steel slide if the holster isn’t dried and conditioned regularly, and its retention loosens with wear in a way you can’t dial back with a screw the way you can on Kydex. Hybrid holsters — a leather or fabric backer against your body with a Kydex or similar shell holding the gun — are the most common IWB choice today precisely because they split the difference: comfort from the backer, adjustable retention and a rigid open mouth from the shell. Nylon holsters are the budget option; they’re light and cheap but nearly always lack an adjustable retention screw and the mouth collapses once the gun is drawn, which matters more than it sounds like — see below.
Why the mouth staying open is a safety feature, not a convenience
A rigid holster mouth (Kydex, hybrid, or well-built leather) stays open after you draw, so reholstering is a controlled, one-handed, look-if-you-need-to motion. A collapsed nylon or worn soft-leather mouth requires using your support hand to hold it open, which means that hand, or your body, ends up near the muzzle during reholstering — the single moment most self-inflicted negligent discharges actually happen, more often than during the draw itself.
Carry position: appendix vs strong-side IWB
Appendix carry (AIWB, roughly 12 to 2 o’clock) gives the fastest presentation and conceals well under an untucked shirt, but it demands full trigger guard coverage without compromise and real awareness of muzzle direction when seated — the muzzle points toward the femoral artery and groin in a seated position, which is why AIWB holsters lean harder on rigid retention and a forward cant than strong-side holsters do. Strong-side IWB (3 to 5 o’clock) is generally more comfortable over a full day, easier to conceal under a wider range of clothing including tucked shirts with the right holster clip, and more forgiving if your build changes seasonally. Both benefit from a claw attachment or wedge, a small add-on that levers the grip in against your body to kill printing at the beltline.
Belt and support
An IWB holster is only as stable as the belt threaded through it. A standard dress or fashion belt sags under the weight of a loaded M&P9 and lets the holster tip outward, which both prints more and slows the draw. A stiff, purpose-built gun belt in the standard 1.5″ width, sized to actually resist bending under the clip’s tension, is not an optional upgrade — it’s the difference between a holster performing as designed and one that doesn’t.
Evaluating a holster yourself
- Full trigger guard coverage with the gun seated — check by looking straight down into the holster mouth.
- The mouth stays rigidly open after the gun is removed, with no need for a second hand.
- Retention is adjustable and gives a distinct, felt click when the gun seats.
- The holster holds the gun securely upside-down and while you jump in place — a real test, not a formality.
- It’s comfortable enough, on the belt you’ll actually wear, for eight-plus hours before you commit to carrying it daily.
Concealed carry laws, permit requirements, and where you’re legally allowed to carry vary by state and even by locality — this is general fit and equipment guidance, not legal advice, so confirm your own jurisdiction’s rules separately.