Three hypotheses concerning negative social interaction in later life were evaluated in this study. First, it was predicted that greater personal economic difficulty is associated with more frequent negative social interaction with social network members in general. Secondly, it was proposed that more frequent negative social interaction exacerbates the undesirable effect of personal financial strain on change in self-rated health during late life. Thirdly, an effort was made to see if some types of negative social interaction, but not others, accentuate the undesirable effects of personal economic problems on self-rated health. Data from two nationwide longitudinal surveys that were conducted in the United States revealed that greater personal financial difficulty is associated with more interpersonal conflict. The findings further indicate that the undesirable effects of personal economic difficulty on change in self-rated health are more pronounced at progressively higher levels of negative social interaction. Finally, the data suggest that one form of negative social interaction (not getting help when it is expected) is more likely to intensify the unwanted effects of personal financial strain on self-rated health than other types of negative social interaction.