(Assuming the MS Word version is up-to-date and the most current version of Adobe Acrobat DC is installed.)
Create your document in Microsoft Word, making sure you’ve taken all of the accessibility steps necessary and the document has passed the Microsoft Accessibility Checker.
If your version of Acrobat was installed correctly, there should be an Acrobat tab in your version of Microsoft Word for Mac.
The command you’ll use to create your accessible PDF will be “Create PDF” at the far left of the Acrobat dropdown in MS Word.
Now click “Create PDF” to save a tagged PDF version of your MS Word document.
You should get a pop-up similar to the one below. (This is also the window that pops up when you click “Preferences.”) It’s asking if you want to use the Acrobat online service to create the PDF. Nine times out of ten, the best answer to this question is “Yes.” The process takes the same amount of time, whichever option is chosen.
As it’s processing, you should see a status window with a progress bar:
If you choose “No” in the dialog above, a Save dialog similar to the one below will pop up, allowing you to name your document, designate the save location, etc.
(Don’t choose “Best for printing” because tags won’t be generated.)
Click “Export” and the PDF will be created in the location and under the filename you specified.
You should see a dialog box similar to the one below as it’s processing.
It’s always best to go back and check the PDF for accessibility features like tags, etc. If you need to make content-level changes, be sure to do so in Microsoft Word and then re-save as a PDF.