The integration of the U.S. National Grid (USNG) coordinates in online web mapping systems has only been partially implemented on a variety of web mapping pages. When not in possession of USNG standardized printed map products, one of the most difficult things to do is to take a USNG coordinate and quickly produce a basic, readable map, or visa versa: take a basic map or address and obtain a USNG coordinate.
Due to the Google Maps billing changes coming in summer of 2018, the demonstration site is highly likely to stop working or malfunctio. Details about the changes can be found here: https://developers.google.com/maps/billing/important-updates
Contributors include Mike Dolbow and Sean Gutknecht. A demonstration page can be used at http://mmdolbow.github.io/usng-gmap-v3/ This page is ONLY intended as a demonstration. Individuals and organizations should NOT use the demo page in production or mission-critical situations. Organizations may want to consider hosting this code on their own or hiring a consultant to build something for them. I recommend https://mappingsupport.com/ to find someone familiar with building similar functionality.