Zotero comes with a number of frequently used citation styles ready for use. However, the citation style of your choice may not be there. If that happens to you, check out the Zotero Style Repository: zotero.org/styles

A web browser displaying the "Zotero Style Repository" website.

Use the 'Style Search' box to search for a citation style.

Consider searching for a citation style by that style's full name, commonly used abbreviation, or name of a journal that uses that style.

The "Zotero Style Repository" website, displaying search terms entered into the search box, and a few results found.

There may be several citation styles listed with a similar name. Hover your cursor over a hyperlinked citation style to get a preview of that citation style, applied to several different types of sources.

The "Zotero Style Repository" website, displaying a pop-up preview of a particular citation style.

When you've decided which one to add, click on it directly.

Zotero will ask if you'd like to add the citation style. Click 'OK.'

The "Zotero Style Repository" website, displaying a popup that asks "Add citation style to Zotero?"

When you next try to cite in Microsoft Word, that citation style will be among your options to choose from.