<PAGE>
<TABLE>
<CAPTION>
<S> <C>
Pricing Supplement No. 12 Dated February 12, 1999 Filed Pursuant to: Rule 424(b)(3)
(To Prospectus dated October 27, 1998 and File No.: 333-38387-99
Prospectus Supplement dated November 4, 1998)
</TABLE>
BANK ONE CORPORATION
MEDIUM-TERM NOTES, SERIES A
<TABLE>
<S> <C> <C> <C>
Date of Issue: 2/17/99 [X] Fixed Rate [ ] Commercial Paper Rate Note [ ] LIBOR Reuters
[ ] Senior [ ] Federal Funds Rate Note [ ] LIBOR Telerate
Maturity Date: 2/17/09 [X] Subordinated [ ] CD Rate Note [ ] Prime Rate Note
[ ] CMT Rate Note [ ] Treasury Rate Note
[ ] LIBOR Note [ ] Other
</TABLE>
CUSIP: 06422OAA7
Principal Amount: $350,000,000.00
Issue Price (As a Percentage of Principal Amount): 99.621%
Interest Rate/Initial Interest Rate: 6.0%
Interest Payment Dates: 17th Day of February and August of each year
Interest Reset Dates: None
Index Maturity: None
Designated CMT Maturity Index: None
Designated CMT Telerate Page: None
Spread: None
Spread Multiplier: None
Minimum Interest Rate: None
Maximum Interest Rate: None
Interest Payment Period: None
Interest Rate Reset Period: None
Redemption Date(s) or Period: None
Optional Repayment Date(s): None
Calculation Agent (If Applicable): None
Additional Terms:
As of September 30, 1998, the aggregate amount of Senior Indebtedness and
General Obligations of the Company was approximately $7.9 billion.
This Pricing Supplement may be used by First Chicago Capital Markets, Inc.
("FCCM") and Banc One Capital Markets, Inc. ("BOCM"), wholly owned subsidiaries
of the issuer, in connection with offer and sales related to secondary market
transactions in the Notes. FCCM and BOCM may act as principal or agent in such
transactions. Such sales will be made at prices related to the prevailing market
prices at the time of sale.
