The best source of information on the population status of Lesser Yellowlegs is migration monitoring by the Program for Regional and International Shorebird Monitoring (PRISM). As this species tends not to concentrate in large flocks at the migratory stopover sites covered by the survey, coverage and therefore reliability are likely medium at best. PRISM data indicate a large long-term decrease in abundance since the early 1970s, resulting in a cumulative decline of 76%. Breeding Bird Survey (BBS) data also provides information on this species, but reliability is constrained by low coverage in the northern parts of its range, and precision is marginally lower than from PRISM. However, the 74% loss since 1970 indicated by the BBS is highly similar to the PRISM trend, allowing for high confidence that there was been a large decline.

The goal for Lesser Yellowlegs is to increase the population to the level it was at in the early 1980s, based on migration monitoring by the Program for Regional and International Shorebird Monitoring. Trend data show that Lesser Yellowlegs is far below its goal range and its population decline is ongoing. The trend will need to stabilize before the population can begin to rebound, and it is not realistic for the goal to be met by 2050. Based on analysis of the historical population loss and potential growth rates, the interim target is to reach 25% of the goal by that year. Achieving this target, and ultimately reaching the national goal for this species, will require ambitious and long-term conservation action.