The SFS slide fire kit made it left handed I don't think S&W ever made a left hand 15-22

Smith & Wesson M&P 15-22 AR-Style .22 Long Rifle 16 Inch Barrel With Slide Fire Standard Battle Stock Left Handed Matte Black 25 Round(Because of slide fire stock). Smith and Wesson Customer Service/Product Information should be able to answer the LH aspect and if a LH rifle is or will be available at (USA) 1-800-331-0852
Mon-Fri 8:00AM-8:00PM Eastern Time

Caliber: .22LR - Stock: Slide Fire® SSAR-15® MOD - Trigger: 3.5lb Curved Trigger - Attachment: Recoil Enhancer - Capacity: 25 Round Detachable Mag - Action: Blow Back Semi-Auto - Barrel Length: 16 - Barrel Twist: 1 in 15 - Front Sight: Adjustable A2 Post - Rear Sight: Adjustable Dual Aperture - Weight: 5.5 lbs. - Barrel Material: Carbon Steel - Finish: Matte Black - FEATURES - Two-Position Receiver Mounted Safety Lever - Functioning Charging Handle - Bolt Catch - Recessed Magazine Release - Ambidextrous Load-Assist Button - Lightweight High-Strength Polymer - Upper and Lower Receiver with Integral Steel Inserts - Lightweight High-Strength Polymer - Quad Rail Handguard