Resistance of pile groups to lateral loads indicate that pile spacings less than about 8 pile diameters in the direction of loading reduce the soil modulus. The reduction factors are assumed to vary linearly from 1 at 8 diameters to 0,25 at 3 diameters spacing if the number of piles in the group is 5 or more and the passive resistance of the pile cap is ignored. The effect of this reduction is to “soften” the soil reaction and produce smaller lateral resistance for a given group deflection.