The third seed will step out on the new Louis Armstrong Stadium against Russia's Evgeniya Rodina on Monday looking to continue the New York fairy tale that swept her to an improbable title success 12 months ago.
Only just back from a serious foot injury, Stephens arrived at Flushing Meadows ranked 83 and left as America's newest grand slam champion.
She's 9/1 to defend her title with Sky Bet, who have boosted the odds of every player in advance of the tournament.
Stephens said: "I've been back (to Flushing Meadows) about four or five times now. For me, being here is super cool, obviously. But as defending champion, obviously (there is) a lot of stress, a lot of pressure.
"I'm just going to go out and handle it as best I can, just try to play my best. It's a completely new tournament this year."
Backing up such unexpected success is notoriously difficult, and Stephens did not win another match until the end of February, suffering eight successive losses, but since then she has shown her Flushing Meadows triumph was no fluke.
The 25-year-old won the biggest WTA Tour title of her career in Miami in March before reaching a second slam final at the French Open, this time losing to Simona Halep.
Her form on the North American hard courts has also been encouraging, with a final appearance in Montreal, and even an early loss at Flushing Meadows would not see her fall far in the rankings.
She is proud of how she has coped with the mantle of grand slam champion, saying: "I think I handled it the best that I could. I've just made the most of it, tried to keep my tennis first. That's really all you can do. I'm proud of my results. I just hope to keep going forward, have some more success.
"I would love to do well here. Obviously as an American, any American wants to do well here. Having good results in previous tournaments has definitely helped. I'm waiting on all these points to drop off, I'll have a little bit of a cushion."
Stephens is one of 13 current or former slam champions in the women's draw and six others also begin their campaigns on Monday.
There will be a first-round meeting between two of them on Arthur Ashe as Venus Williams takes on Svetlana Kuznetsova before Serena Williams makes her US Open comeback against Magda Linette to open the night session.
Top seed Simona Halep faces Kaia Kanepi on Armstrong while Victoria Azarenka and Garbine Muguruza are also in action.
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