The Marsh Protection Potential Index (MPPI) ranks Maryland’s coastal marshes by their ability to protect vulnerable communities from coastal hazards. To do so, we identified five key questions to assess each marsh: How much is the marsh able to reduce the impact of coastal hazards? Is the marsh located where coastal hazards are a threat? Is the marsh located where there are people to protect? Is the marsh located adjacent to other protective habitats? Is the marsh likely to survive in the face of rising sea levels? Using data from the Coastal Resiliency Assessment and other sources, we developed metrics to score each marsh on these five questions. Then, the sub-scores were combined to create the Marsh Protection Potential Index overall rating, which ranks the protective ability of over 14,000 marshes statewide. It is important to note that the MPPI ranks marshes relative to other marshes, rather than providing an absolute measure of protective services. The Marsh Protection Potential Index does not attempt to describe the dollar-value of protective services provided by each marsh, nor does it compare marshes to other types of habitat or to other protection infrastructure solutions. In addition, the MPPI does not assess marshes on any of the other characteristics that often inform conservation priorities. Things like biodiversity, ecosystem health, rare species, recreation value, or water quality services are often important to stakeholders, and these are not captured by the MPPI. The MPPI is intended to supplement, not replace, the other ways conservation decision-makers prioritize natural habitats.