Deutsche Asset Management [LOGO]
                                             A Member of the Deutsche Bank Group






Chief Executive Officer
Section 906 Certification under Sarbanes Oxley Act






I, Julian Sluyters, certify that:

1.   I have reviewed this report, filed on behalf of Montgomery Street Income
     Securities, Inc., on Form N-CSR;

2.   Based on my knowledge and pursuant to 18 U.S.C. ss. 1350, the periodic
     report on Form N-CSR (the "Report") fully complies with the requirements of
     ss. 13 (a) or ss. 15 (d), as applicable, of the Securities Exchange Act of
     1934 and that the information contained in the Report fairly presents, in
     all material respects, the financial condition and results of operations of
     the Company.




August 23, 2004                                       /s/Julian Sluyters
                                                      Julian Sluyters
                                                      Chief Executive Officer
                                                      Montgomery Street Income
                                                      Securities, Inc.




                                                Deutsche Asset Management [LOGO]
                                             A Member of the Deutsche Bank Group







Chief Financial Officer
Section 906 Certification under Sarbanes Oxley Act






I, Charles A. Rizzo, certify that:

1.   I have reviewed this report, filed on behalf of Montgomery Street Income
     Securities, Inc., on Form N-CSR;

2.   Based on my knowledge and pursuant to 18 U.S.C. ss. 1350, the periodic
     report on Form N-CSR (the "Report") fully complies with the requirements of
     ss. 13 (a) or ss. 15 (d), as applicable, of the Securities Exchange Act of
     1934 and that the information contained in the Report fairly presents, in
     all material respects, the financial condition and results of operations of
     the Company.




August 23, 2004                                  /s/Charles A. Rizzo
                                                 Charles A. Rizzo
                                                 Chief Financial Officer
                                                 Montgomery Street Income
                                                 Securities, Inc.