New mission designs, advances in science and technology, and the entrance of new actors has raised concerns with the applicability of planetary protection to modern space activities. Planetary protection is a term that generally refers to the practice of avoiding contamination of other celestial bodies by terrestrial lifeforms or organic compounds (so-called “forward contamination”) and avoiding contamination of the Earth by extra-terrestrial biological organisms (“backward contamination”). In this document, we review current planetary protection policies and approaches; summarize current U.S. and international law, regulation, standards, policies and practices governing planetary protection; assess relevant authorities, challenges, and opportunities for change; and provide policy options for reviewing and updating, as necessary, national planetary protection policies.