I was on the line with a Citibank customer service representative just now who was cooperative enough to stay online to connect with MasterCard. While we were all on the phone together, the MasterCard representative checked and stated, unequivocally, that Citibank does not participate in the MasterCard SecureCode program. Consequently, if you are trying to purchase from an online source (in my case, the Austrian railroad ÖBB), you will have to use another credit card.

Numerous Citibank customer service representatives had no idea what I was talking about or gave incorrect information stating that Citibank did participate in MasterCard Securecode.