The Interior Design Reference Manual by David Kent Ballast is the BEST textbook for your NCIDQ exam studies. It covers content for all three exams and is available in both a physical book format as well as a digital subscription.

The publisher Kaplan PPI has stated that they are NOT publishing an updated textbook at this time for the new 2026 exam format. They have instead issued updated "Content Maps" that connect the new exam blueprint topics to chapters in the 7th edition of the textbook. You can download these Content Maps by joining our Free Online Community!

Also from this publisher: IDFX Flashcards, IDPX Flashcards, IDFX Mock Exam, IDPX Mock Exam, PRAC Mock Exam (now IDIX) - none of these materials have been updated for the new exam either, but some designers still find them helpful