Bank of America, Barclay's, Chase, and Citibank are all MasterCard issuers.
Many Citicard applications allow the customer to choose which version to receive.
By default, Chase personal cards are issued as VISA, but you can obtain a MasterCard version if you start the application process here:
http://www.mastercard.us/personal-select.html
By default, Chase Ink (small business) cards are issued as MasterCard.