Dancing With the Stars' Lacey Schwimmer has gone under the knife to increase her boob size, according to Us.

A source tells the mag:

    "Lacey's told friends she got a boob job. She'd wanted one for a while so she went ahead and did it. She loves the results and she's proud of her new shape."

Schwimmer, 23, reportedly went from a B to a D cup. This past season on DWTS, she was partnered with Chaz Bono.

The source adds the dancer wasn't happy with her athletic build ... and instead, wanted a model shape. Some online reports are also claiming Lacey had a nose job and her lips enhanced, as well.