PROSPECTUS SUPPLEMENT                                         File No. 333-38792
- ---------------------                                             Rule 424(b)(3)
(To Prospectus Supplement and Prospectus dated
June 16, 2000 and June 15, 2000, respectively)
Prospectus number:      2073


                             Merrill Lynch & Co., Inc.
                           Medium Term Notes, Series B
                   Due Nine Months or More from Date of Issue


                               Floating Rate Notes


Principal Amount:  $25,000,000        Original Issue Date:    January 19, 2001

CUSIP Number:      59018Y DM0         Stated Maturity Date:   January 21, 2003

Interest Calculation:                  Day Count Convention:
- ---------------------                  ---------------------
[X]  Regular Floating Rate Note        [X]  Actual/360

[ ]  Inverse Floating Rate Note        [ ]  30/360

       (Fixed Interest Rate):          [ ]  Actual/Actual

Interest Rate Basis:
- --------------------
[ ]  LIBOR                             [ ]  Commercial Paper Rate

[ ]  CMT Rate                          [ ]  Eleventh District Cost of Funds Rate

[ ]  Prime Rate                        [ ]  CD Rate

[X]  Federal Funds Rate                [ ]  Other (see attached)

[ ]  Treasury Rate

   Designated CMT Page:                Designated LIBOR Page:
        CMT Telerate Page:                  LIBOR Telerate Page:
        CMT Reuters Page:                   LIBOR Reuters Page:


Index Maturity:          Not Applicable    Minimum Interest Rate: Not Applicable

Spread:                  0.360%            Maximum Interest Rate: Not Applicable

Initial Interest Rate:   TBD               Spread Multiplier:     Not Applicable


Interest Reset Dates:      Daily, commencing January 19, 2001 through the
                           maturity date; subject to the following business day
                           convention

Interest Payment Dates:    Quarterly, on the 21st of April, July, October and
                           January commencing April 21, 2001; subject to the
                           following business day convention

Repayment at the
Option of the Holder:      The Notes cannot be repaid prior to the Stated
                           Maturity Date.


Redemption at the
Option of the Company:     The Notes cannot be redeemed prior to the Stated
                           Maturity Date.

Form:                      The Notes are being issued in fully registered
                           book-entry form.

Trustee:                   The Chase Manhattan Bank

Dated:                     January 16, 2001