On behalf of the American public, federal agencies take many actions that influence ecosystem conditions and change the provision of ecosystem services valued by the public. To date, most decisions affecting ecosystems have relied on ecological assessments with little or no consideration of the value of ecosystem services. Best practice for ecosystem services assessments is to apply quantitative measures and methods that express both an ecosystem’s capacity to provide valued services and, through those services, social benefit (value). Well-established preference evaluation methods, including market and non-market economic valuation as well as non-monetary methods, can be used to estimate values for ecosystem services. Such preference evaluation methods are sometimes used by federal agencies and represent best practice for ecosystem services assessment. However, these methods can be infeasible because of time or resource constraints, particularly when new data need to be collected. In such cases, the minimum standard recommended for an ecosystem services assessment is to use measures that go beyond narrative description and that are carefully constructed to reflect the ecosystem’s capacity to provide benefits to society but that stop short of a formal assessment of people’s preferences. We call these measures of ecosystem services benefitrelevant indicators (BRIs). The use of BRIs ensures that ecosystem services assessments measure outcomes that are demonstrably relevant to human welfare, rather than biophysical measures that might not be relevant to human welfare. Examples of BRIs include likelihood or occurrences of respiratory distress caused by wildfire smoke inhalation, number of bald eagle nests (an iconic species), and storage volume of wetland areas upstream of homes vulnerable to floods. If ecosystem service values or BRIs are not used in some manner, ecosystem services are not being assessed, and no direct insights can be drawn about effects on social welfare. This minimum best practice is broadly achievable across agencies and decision contexts with current capacity and resources.