The Guide Specifications for Internal Redundancy of Mechanically-Fastened Built-Up Steel Members, 1st Edition (Item Code: GSBSM-1), published in 2018, provides an analytical framework to evaluate the internal redundancy of typical steel bridge members, and designate primary steel members as Fracture Critical Members (FCMs) or Internally Redundant Members (IRMs). They describe a procedure for evaluating the internal redundancy of the built-up tension members of the tension components of flexural members and axially loaded tension members. These 2025 Interim Revisions (Item Code: GSBSM-1-I2) include new rules finalized by the Federal Highway Administration in 2022 that pertain to the National Bridge Inspection Standards, including replacing the term “fracture critical member (FCM)” with the term “nonredundant steel tension member (NSTM)." It is necessary to have these 2025 Interim Revisions, as well as the 2022 Interim Revisions (Item Code: GSBSM-1-I1), to have all current specification information.