It's best to save a word file to PDF but only after the word file has been properly configured for accessibility.

Word files present a security issue because they are much more easy to edit and alter once downloaded than PDF files, so if for some reason it's not possible to create a PDF and the content is required to be delivered in a regulated format, apply security settings to the Word File, using Word's document protection.

Accessible Word Document Requirements

A Word document is accessible if:

• it has a table of contents (for long documents).
• is has hierarchy of headings for clarity and understanding.
• lists are created using the editor list function.
• tables have designated headings, and complex tables use table alt tag/summary to add extra information for screen readers.
• important images have informative alt tags so they are understandable when not seen.
• unimportant images and graphics have empty alt tags so they can be skipped.
• text effects that are not accessible are avoided (Text Box, Quick Parts, WordArt, and Drop Caps are not accessible formatting tools in Mac or PC).

Resources

• Penn State Accessibility Word Tips
• Penn State Mac Office to tagged PDF

Testing Techniques

Word 2010 comes with an accessibility checker that can help find a few overlooked accessibility items in a document, but it will not locate most problems. To run Microsoft Word's accessibility checker, select File, then click the Info tab on the left-hand side of the screen. Then click on the Check for Issues button and select Check Accessibility.