OshKosh B'Gosh ha Buy One, Get One Free Entire Site & Store! Offer good through 4/23! Offer excludes clearance, Doorbusters and OKBG Exclusives, but there are some deals to be had with this offer!
There's no code to enter. Just add items to your cart and the discount will automatically be applied!
Source:
http://www.bargainhuntingmoms.com/2013/04/oshkosh-buy-one-get-one-free-.html