Lehmann outlined his plans to Fox Sports, declaring the English summer season in 18 months will be his last hurrah.
Australia will seek to defend their World Cup title in the first half of the 2019 English season before playing an Ashes Test series.
"That will be it," Lehmann said when asked whether he will seek a new contract beyond 2019.
"It will be a case of too much time, too much travel."
Lehmann has been at the helm since the 2013 Ashes when he replaced sacked coach Mickey Arthur following a disastrous tour of India.
In Lehmann's time as coach, Australia have won two Ashes series at home and lost two in England, while also winning the 2015 World Cup.
"For me, I've really enjoyed the role and loving it," he said.
"We'll just get to that point and work out what we do from there."
Former Test opener Justin Langer, who has an outstanding record at Western Australia and the Perth Scorchers, will be among the favourites to succeed Lehmann as national coach.
First Published: December 25, 2017, 8:59 AM IST