The writer told TV Line that 2013 will be "an amazing year" for fans of the sci-fi drama.
Moffat explained: "I've got various plans, but all I can say emphatically is it will be huge. There's lot of decisions we're making that are about making all that possible. It'll be amazing."
Moffat also confirmed that plans for the anniversary extend beyond a one-off special episode.
"It won't be just one thing, we'll be doing lots of stuff," he hinted. "The plans are quite extensive, and changing all the time. Oh my God, we will hit that year very, very hard indeed."
However, Moffat added that his ideas for 2013 are still at a very early stage of development.
"It's so far in the future, [so] it's only a set of notions," he said.
Doctor Who star Matt Smith recently revealed that he is keen to film an episode featuring multiple Doctors for the 50th anniversary.
Doctor Who will return to BBC America in the US on August 27 and will likely air on the same day on BBC One in the UK.
> Doctor Who Matt Smith: 'Let's Kill Hitler is best episode yet'
Watch a trailer for the new episodes of Doctor Who below: