WASHINGTON – You know you’ve hit it big in the fashion world when Michelle Obama, first lady and fashion icon, starts wearing your dresses. (Remember, Jason Wu?)

Michelle Ochs and her business partner, Carly Cushnie, have hit it big.

Ochs, a 27-year-old designer, was surprised when a stylist from Obama’s office reached out to her and Cushnie in November about designing a dress for Obama. Ochs said she had “no idea when or where” the dress would be worn, and she isn’t quite sure how their line, Cushnie et Ochs, caught the stylist’s eye. She and Cushnie had one week to design the outfit, have it made and get it to Washington; they met their deadline.

“Mrs. Obama wearing our dress this year was the highlight to what was already an amazing year, looking forward to 2012,” the designers wrote on their Facebook page after Obama wore their forest green dress to a Christmas concert.

The year seems to be in their favor. Ochs and Cushnie will show their fall 2012 collection Friday at New York Fashion Week. The event will be live-streamed online. Recently, the duo completed their pre-fall 2012 line, which is already causing a buzz online.

The collection, inspired by the 1967 French film “Belle du Jour,” has “a little bit of lace, little bit of corseting . . . a little bit of the evolution of the flair,” Ochs says.

The see-through tops and body-hugging dresses are a far cry from the uniforms Ochs got used to wearing while attending private schools in Washington. (She was reprimanded a time or two at St. John’s College High School for breaking the dress code by wearing nail polish.) Ochs lives in New York now, but you can still see traces of her D.C. roots in her work.

“Growing up, there was a lot of ‘this is what’s appropriate, this wasn’t,’ “ she says. “A lot of that kind of refinement and way of dressing really stuck with me.”

While Cushnie et Ochs can be edgy with its almost backless dresses, angled bust lines and bold red tops, some of that refinement pops up in its calf-length dresses and skirts.

Ochs says having a first lady who has kind of changed the rules on what’s wearable in Washington has opened new doors for lesser-known designers.

“Whether she knew or didn’t know . . . she’s really helped young designers,” Ochs says. “You used to never hear any first lady wearing things by a designer that wasn’t mass known.”

It’s the versatility of the collection’s pieces, Ochs says, that makes them appealing to professionals.

Women “appreciate a beautiful dress that you’re not just going to wear once,” she says. “We definitely want it to be pieces that she’ll have for the long term.”

Chances are low that Obama will make another television appearance in the Cushnie et Ochs custom-made silk crepe dress. But that may not be such a bad thing. Instead of wearing one Jason Wu dress numerous times, she wore a few of his items. And look where that got him.