Mass timber (MT) products, such as Glued Laminated Timber (GLT), Cross Laminated Timber (CLT), Laminated Veneer Lumber (LVL), Nail Laminated Timber (NLT), Dowel Laminated Timber (DLT), Laminated Strand Lumber (LSL), Parallel Strand Lumber (PSL), Mass Plywood Panels (MPP) and others, provide options for developing efficient structural systems to resist gravity and lateral loads. Such systems can be competitive alternatives to their steel and concrete counterparts. This InfoNote briefly introduces the MT Seismic Force Resisting Systems (SFRSs) that will be implemented in the 2020 National Building Code (NBC) of Canada, their height limits, and the main design requirements according to Canadian Standard for Engineering Design in Wood CSA O86-19. Differences among height limits for MT gravity and lateral load resisting systems are also discussed.