The future rate and extent of sea level rise are highly uncertain, and responses to higher water levels will need to reflect this uncertainty. Sea level rise was a major topic of the annual meeting of the National Academy of Engineering on October 9-10, 2016, and the second day featured a forum on adaptation to it. This summary of the forum, which also incorporates material from Robert J. Nicholls' plenary presentation, outlines a rich and challenging set of problems for engineers, scientists, and those who work with them.