A remote pilot maintains currency by completing:

The remote pilot certificate itself does not expire; what expires is the pilot's currency to exercise its privileges, and that is maintained by completing recurrent training within the previous 24 calendar months. The training is a free online course covering the same knowledge areas as the initial test, taken through the FAA's training system, with the completion recorded — there is no in-person test, no examiner and no fee. Understanding the structure matters because the alternatives in a question like this describe the certification regime for manned pilots: a flight review with an examiner, a medical certificate, recent flight experience requirements. None of those apply to a remote pilot. Calendar months matter too: currency runs to the end of the 24th month, not to the anniversary date, which gives a small but real margin.

A remote pilot maintains currency by completing recurrent training within the previous 24 calendar months, taken online with no test, examiner or fee.

The remote pilot certificate does not expire, but exercising its privileges requires recurrent training completed within the previous 24 calendar months, taken online through the FAA training system at no cost.

Two Years, Online, Free. No examiner, no medical, no logged hours — that is the manned world.

Note calendar months, not the anniversary date. Currency runs to the end of the 24th calendar month after completion.

• •Confusing certificate validity with currency
• •Importing manned pilot requirements such as a flight review or medical
• •Counting 24 months from the anniversary rather than by calendar month