CERTIFICATION

Pursuant to 18 U.S.C. Section 1350,

As Adopted Pursuant to Section 906

of the Sarbanes-Oxley Act of 2002

The undersigned, the President & CEO of SEI Institutional Managed Trust (the “Trust”), with respect to the Trust’s Report on Form N-CSR for the fiscal year ended September 30, 2018 as filed with the Securities and Exchange Commission, hereby certifies, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that, to the best of my knowledge:

1. such Form N-CSR fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

2. the information contained in such Form N-CSR fairly presents, in all material respects, the financial condition and results of operations of the Fund.

Dated: December 7, 2018

/s/ Robert A. Nesher

Robert A. Nesher

President & CEO

CERTIFICATION

Pursuant to 18 U.S.C. Section 1350,

As Adopted Pursuant to Section 906

of the Sarbanes-Oxley Act of 2002

The undersigned, the Controller & CFO of SEI Institutional Managed Trust (the “Trust”), with respect to the Trust’s Report on Form N-CSR for the fiscal year ended September 30, 2018 filed with the Securities and Exchange Commission, hereby certifies, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that, to the best of my knowledge:

1. such Form N-CSR fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

2. the information contained in such Form N-CSR fairly presents, in all material respects, the financial condition and results of operations of the Fund.

Dated: December 7, 2018

/s/ James J. Hoffmayer

James J. Hoffmayer

Controller & CFO