Pricing Supplement No. 55 dated January 25, 2005
(to Prospectus dated August 6, 2003
and Prospectus Supplement dated August 6, 2003)		   Filed under Rule 424(b)(3)
File No. 333-107132

SLM Corporation
Medium Term Notes, Series A
Due 9 Months or Longer From the Date of Issue


Principal Amount:
 
$1,000,000,000
 
Floating Rate Notes:
ý
 
Fixed Rate Notes:
o

Original Issue Date:
 
February 1, 2005
 
Closing Date: February 1, 2005
 
CUSIP Number:
78442F DH 8

Maturity Date:
 
January 25, 2008
 
Option to Extend Maturity:
ý No
o Yes
 
Specified Currency:
U.S. Dollars
        If Yes, Final Maturity
Date:		        

Redeemable at the option of the Company:   ý No   Redemption Price: Not Applicable.
    o Yes   Redemption Dates: Not Applicable.
Repayment at the option of the Holder:   ý No   Repayment Price: Not Applicable.
    o Yes   Repayment Dates: Not Applicable.

Applicable to Floating Rate Notes Only:
Floating Rate Index:      
o     CD Rate   Index Maturity:                Three Months.
o     Commercial Paper Rate      
o     CMT Rate   Spread:        Plus 8 basis points (0.08%).
o     Federal Funds Rate      
ý     LIBOR Telerate   Initial Interest Rate:        TBD.
o     LIBOR Reuters      
o     Prime Rate   Interest Rate Reset Period:        Quarterly.
o     91-Day Treasury Bill Rate      
Reset Date(s): Each January 25th, April 25th, July 25th and October 25th during the term of the Notes, subject to adjustment in accordance with the following business day convention, beginning April 25, 2005.   Interest Payment
Date(s):		 Each January 25th, April 25th, July 25th and October 25th during the term of the Notes, subject to adjustment in accordance with the following business day convention, beginning April 25, 2005.

ABN AMRO Incorporated
BNP PARIBAS
Goldman, Sachs & Co.
Morgan Stanley
UBS Investment Bank
Banc of America Securities LLC
Citigroup
HSBC
RBC Capital Markets
Barclays Capital
Credit Suisse First Boston
Merrill Lynch & Co.
RBS Greenwich Capital
Wachovia Securities

January 25, 2005

MTN 0100

Interest Determination
Date(s):		 2 London and New York Business Days prior to the related Reset Date (or Original Issue Date in the case of the First Interest Period).   Interest Period(s): From and including the previous Interest Payment Date (or Original Issue Date, in the case of the first Interest Period) to but excluding the current Interest Payment Date (or Maturity Date, in the case of the last Interest Period).
Lock-in Period Start Date: Not Applicable.   Accrual Method: Actual/360.
Maximum Interest Rate: Not Applicable.   Minimum Interest Rate: Not Applicable.

Form:
Book-entry.

Denominations:
$1,000 minimum and integral multiples of $1,000 in excess thereof.

Trustee:
JPMorgan Chase Bank, N.A., formerly known as JPMorgan Chase Bank and The Chase Manhattan Bank.

Agents:
The following agents are acting as underwriters in connection with this issuance.

 
                                Agents
 
Principal Amount of Notes

 
Merrill Lynch, Pierce, Fenner & Smith Incorporated
 
$   150,000,000.00    
  Citigroup Global Markets Inc.        145,000,000.00    
  Goldman, Sachs & Co.        125,000,000.00    
  Barclays Capital Inc.        122,000,000.00    
  UBS Securities LLC        115,000,000.00    
  Banc of America Securities LLC          75,000,000.00    
  BNP Paribas Securities Corp.          75,000,000.00    
  Morgan Stanley & Co. Incorporated          75,000,000.00    
  Wachovia Capital Markets, LLC          40,000,000.00    
  Credit Suisse First Boston LLC          25,000,000.00    
  Greenwich Capital Markets, Inc.          25,000,000.00    
  HSBC Securities (USA) Inc.          15,000,000.00    
  ABN AMRO Incorporated          10,000,000.00    
  RBC Capital Markets Corporation            3,000,000.00    
          Total   $1,000,000,000.00    

Issue Price:
100.0%.

Agents' Commission:
0.06%.

Net Proceeds:
$999,400,000.

Concession:
0.04%.

Reallowance:
0.03%.

CUSIP Number:
78442F DH 8.

ISIN Number:
US78442FDH82.

Obligations of SLM Corporation and any subsidiary of SLM Corporation are not guaranteed by the full faith and credit of the United States of America. Neither SLM Corporation nor any subsidiary of SLM Corporation is a government-sponsored enterprise or an instrumentality of
the United States of America.

MTN 0100

2