Visa on Arrival fee exemption was implemented between November 15, 2018 and January 13, 2019 so far. However, now the Cabinet announced that Thailand Visa on Arrival fee exemption will be extended until April 30, 2019. If you are planning to celebrate Chinese New Year or Songkran Festival in Thailand, now you can make it significantly cheaper!
An extension of Visa on Arrival fee exemption was published by the Cabinet on 8th of January, 2019. Visa on Arrival fee waiver extension from 14 January 2019 to 30 April 2019 IS FINALLY CONFIRMED. Confirmation in the Royal Gazette (in Thai language) can be found here: Visa on Arrival Fee Exemption Confirmation.