(Assuming the MS Word version is up-to-date and the most current version of Adobe Acrobat DC is installed.)
If your version of Acrobat was installed correctly, there should be an Acrobat tab in your version of Microsoft Word.
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.
Before doing so, though, it might be best to check the Preferences, so the conversion happens exactly the way you want it to.
(Preferences is immediately to the right of Create PDF in the Acrobat dropdown.)
The window pictured below should then pop up. Of all the features that can be enabled/disabled, the most important checkbox (with regard to accessibility) is the Enable Advanced Tagging option. Make sure that box is checked.
(Don’t forget to click “OK” when you’ve finished.)
Now click “Create PDF” to save a tagged PDF version of your MS Word document. A Save dialog similar to the one below will pop up, allowing you to name your document, designate the save location, etc.
Note the Options button to the left of Save. This is another chance to double-check the settings and make sure the tags generated by MS Word will accompany the rest of the document’s metadata into the finished PDF.
Make sure “Enable Accessibility and Reflow with tagged Adobe PDF” is checked, even if it appears grayed-out like the example below. (The graying simply means the ability to un-check the selection is locked. As long as a grayed-out checkmark appears in the box, you’re good to go.)
Click “OK” and the PDF will be created in the location and under the filename you specified.
As it’s processing, you should see a status window with a progress bar:
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.