New static and dynamic displacement-based procedures have been developed by the Federal Emergency Management Agency (FEMA) for the seismic evaluation and design of buildings. The static procedures calculate displacements in yielding buildings as the product of an elastic spectral displacement and coefficients C i . Mean elastic and mean inelastic displacements are assumed to be equal for elastic periods, T 0 , greater than the characteristic site period, T g . The data presented in this paper and elsewhere support this assumption for values of the strength ratio greater than or equal to 0โ
20. For T 0 T g , mean inelastic displacements can substantially exceed mean elastic displacements for all values of the strength ratio; FEMA 273 accounts for this observation by the coefficient C 1 . However, the FEMA 273 cap on C 1 (= 1โ
5) is not sufficiently conservative and should be increased to 3โ
0 for the analysis and design of modern construction. The effects of stiffness degradation, strength deterioration and pinching are represented in FEMA 273 by the coefficient C 2 . The values assigned to C 2 appear to be most reasonable. Nonlinear dynamic analysis is being widely used to estimate maximum deformations and displacements in buildings. The values calculated for the maximum deformations and displacements will be dependent upon the means used to characterize structural damping in the building frame. Although structural damping is routinely implemented through a damping constant (or matrix), such an implementation will overestimate the effects of structural damping in a yielding building and underestimate maximum deformations and displacements. Structural damping should be characterized by the target damping ratio (typically 5% of critical) at the point of maximum displacement.