Does your most recent I-20 look like this? If yes, please contact OISS immediately, since these old I-20s will no longer be valid after July 1st!!
The current I-20s do not have a bar code on the first page, so check your documents. All I-20s issued after June 26, 2015, were automatically issued with the redesigned, valid format.
Please remember to keep all your old I-20s. Do not throw any of them away.