In my Word document I have the following bulleted list:



After the colon in each of the list item headers, there is a tab character, and the "L" in "Lorem ipsum" begins at the nearest half-inch interval on the ruler. I want the hanging indent to be right at that half-inch interval point so it will always line up with the "L" in "Lorem ipsum" no matter how long the "List Item" header text is. How do I do this?

As suggested elsewhere, you could specify a hanging indent for the whole list; after the period and underline, just type a space.

__________________
Stefan Blom
Microsoft Word MVP

Microsoft 365 apps for business
Windows 11 Professional

You might also consider why you are effectively using three visual clues to the same structure: bullets, underline – presumably for hyperlinks – and indent …
Looking at the example, I'd have gone for a definition list layout as in the attached screenshot <g>

Attached Images

defList.png (24.8 KB, 15 views)

I strongly agree. Otherwise you will get disjoined (almost random) visual structure.