PROSPECTUS SUPPLEMENT                                         File No. 333-83374
(To Prospectus Supplement and Prospectus dated April 1, 2002)     Rule 424(b)(3)
Prospectus number:   2233

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

                     Floating Rate Notes

Principal Amount:   $100,000,000       Original Issue Date:     June 17, 2002

CUSIP Number:       59018YNB3          Stated Maturity Date:    June 17, 2004

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
|_|   Prime Rate                                  Funds Rate
|X|   Federal Funds Rate                    |_|   CD Rate
|_|   Treasury Rate                         |_|   Other (see attached)
      Designated CMT Page:                        Designated LIBOR Page:
         CMT Telerate Page:                          LIBOR Telerate Page:
         CMT Reuters Page:                           LIBOR Reuters Page:


<TABLE>
<S>                      <C>                                    <C>                      <C>
Index Maturity:          N/A                                    Minimum Interest Rate:   Not Applicable

Spread:                  0.380%                                 Maximum Interest Rate:   Not Applicable

Initial Interest Rate:   Calculated as if the Original Issue    Spread Multiplier:       Not Applicable
                         Date was an interest Reset Date

Interest Reset Dates:    Each Business Day, commencing June 18, 2002 to but excluding the Stated
                         Maturity Date, subject to the following Business Day convention

Interest Payment Dates:  Quarterly, on the 17th of June, September, December and March commencing
                         September 17, 2002; 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:                 JPMorgan Chase Bank

Dated:                   June 6, 2002
</TABLE>