SECTION 906 CERTIFICATION

Pursuant to 18 U.S.C.ss.  1350,  the  undersigned  officers of Federated  Income
Securities   Trust  on  behalf  of:   Federated   Capital   Income  Fund.   (the
"Registrant"),   hereby  certify,  to  the  best  of  our  knowledge,  that  the
Registrant's  Report on Form N-CSR for the period ended  11/30/03 (the "Report")
fully complies with the  requirements  of Section 13(a) or 15(d), as applicable,
of the Securities and 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 Registrant.


Dated: January 27, 2004
/s/ J. Christopher Donahue
Title: President, Principal Executive Officer



Dated: January 27, 2004
/s/ Richard J. Thomas
Title: Treasurer, Principal Financial Officer

This  certification is being furnished solely pursuant to 18 U.S.C.ss.  1350 and
is not being filed as part of the Report or as a separate disclosure document.