USA international Howard is set to make his 200th consecutive Premier League appearance for Everton against Stoke City on Saturday, but Moyes is already making plans for life without the 33-year-old.
The Everton manager is an admirer of Birmingham teenager Butland, who made his England debut against Italy in August, and confirmed goalkeeping coach Chris Woods is helping in the search for Howard's successor.
"You are always planning for who is the next Nigel Martyn, who is the next Tim Howard," said Moyes. "We are always looking to see who that next one would be. You have to do that.
"We have asked a couple of times about Butland, but not recently.
"We are just looking out. Chris Woods is a big part of Tim because he works for the US national team as well, now.
"But Chris also does a lot of work looking at the future goalkeepers for us. It is a bit of a specialist job.
"We can all look at goalkeepers and say 'he comes and catches it' or 'he makes good saves, he has good distribution'. But to understand the technique in goalkeeping is a bit more specialist really."
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