Seismic Force Calculation App

In 2022 USGS decided to discontinue the web service due to insufficient resources and the recent development of similar web tools by third parties, the USGS has replaced its former U.S. Seismic Design Maps web applications with web services that can be used through third-party tools.

https://earthquake.usgs.gov/hazards/designmaps/

Your options for using the replacement USGS web services, which still provide seismic design paramter values from numerous design code editions, are: