Using a national sample of State and local law enforcement agencies, the authors collected survey data about local methamphetamine (meth) markets and related problems, in terms of public safety, health, and the local economy, from narcotic officers in these agencies. The authors hypotheses related to the importance of the structural and interactional organization of meth markets for assessing their impact on the community; the salience of market instability and its potential for leading to more uncertainty for meth buyers, more market conflict, and related community problems; and the relevance of the types of characteristics of the market (e.g., the presence of import or locally supplied meth markets, general market criminality, and use of technology by the market participants) to community public safety, health, and economic problems. The authors found that markets characterized by both imports and locally produced meth are associated with higher levels of problems compared to local-only markets but import-only markets are associated with fewer problems. Meth markets characterized by more criminal activity and greater use of technology by the market participants are significantly associated with higher levels of community problems but market instability and interactional organization were not significant. Also, the market's structural organization was related to community problems. (Published Abstract)