Zacks classifies each company into both sector and industry groups, based on a company's business model.

Sectors are the broadest groups and number 16 in total. Sectors appear in the weekly Industry Rank Analysis. They can also be incorporated into a stock screen via either Research Wizard or the Custom Screener.

Medium (M) industry groups are somewhat smaller in size and number 63 in total. Combining related medium groups creates a sector. Medium groups can be incorporated into a stock screen via Research Wizard. Medium industry groups are also used for categorizing Zacks Equity Research reports by industry.

Expanded (X) industry groups are the smallest in size and number over 250 in total. Combining expanded groups can create either a medium group or an entire sector. Expanded industry groups are used in the Zacks Industry Rank . In addition, these groups can be incorporated into a stock screen via either Research Wizard or the Custom Screener.

The table below shows the mapping of sectors to medium industry groups to expanded industry groups. The codes represent the numerical identifiers for each sector and group.