The Purchasing Managers' Index (PMI) is an indicator of the prevailing direction of economic trends in the manufacturing and service sectors. The indicator is compiled and released monthly by the Institute for Supply Management (ISM), a nonprofit supply management organization.

It is a diffusion index that summarizes whether market conditions are expanding, staying the same, or contracting, as viewed by purchasing managers. The purpose of the PMI is to provide information about current and future business conditions to company decision-makers, analysts, and investors.