The Science Mission Directorate (SMD) has posted some new volunteer reviewer forms on the SARA web page at: https://science.nasa.gov/researchers/volunteer-review-panels

SMD is currently seeking reviewers for:

Earth Science Applications: Water Resources
Emerging Worlds
Solar System Observations
MatISSE and DALI (high-TRL planetary instrument programs)
Astrophysics Research and Analysis
Exoplanet Research Program
Earth Surface and Interior and Space Geodesy Programs
Astrophysics Data Analysis Program

If you would like to volunteer for a review that is not listed above (like Step-1 proposals for B.10 the Heliophysics – Early Career Investigator Program) you may write directly to the Program Officer at: https://science.nasa.gov/researchers/sara/program-officers-list/