Active CPDTs recertify every 2 years. There are no exemptions. If you wish to maintain your CPDT credential you must continue to earn continuing education every 2 years (November 1 through October 31, 24 months later).
Individuals whose CPDT credential has lapses have 18 months from the date of expiration to submit reinstatement documentation and supply the appropriate fee(s). Read more about the CPDT reinstatement process here.
It is administered at testing centers around the world. It is a computer-based exam. Locate a testing center here. ASPE only hosts our examinations at Pearson Professional Centers, so keep this in mind when narrowing down your search.