The ABC comedy has received 14 nominations for this year's awards, having won eight Emmys since 2010.
© ABC
"I think we do worry that people won't root for us as much as they did before we won," Levitan told Deadline, adding: "We're still very much invested in winning and whatever comes with that - winning and what it represents."
The exec producer explained that being nominated for a third year running is a "very strange and new experience".
"You don't want people to think we don't care and [that] we're past that," he said. "But at the same time, you don't want to seem presumptuous.
"This is a very strange and new experience for me - to be in this position where we have won two Emmys in a row and are going for a third. We have to be even better because there will be a lot of people looking to say, 'Where else can I cast my vote?'"
The stars of Modern Family recently sued producers 20th Century Fox Television following unsuccessful contract negotiations, but later struck a new salary deal.
Each member of the show's adult cast is now expected to be paid around $170,000 (£108,000) to $175,000 (£111,000) per episode.
The 2012 Primetime Emmy Awards will air on September 23 on ABC.
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