0001126087 2011-05-01 2012-04-30 0001126087 mist7:S000011096Member 2011-05-01 2012-04-30 2012-04-30 MET INVESTORS SERIES TRUST 0001126087 Other false 2011-12-31 2013-01-25 MET INVESTORS SERIES TRUST SUPPLEMENT DATED JANUARY 25, 2013 TO THE PROSPECTUS DATED APRIL 30, 2012 MFS® RESEARCH INTERNATIONAL PORTFOLIO The following changes are made to the prospectus of MFS® Research International Portfolio (the Portfolio), a series of Met Investors Series Trust. In the Portfolio Summary, the disclosure in the footnote to the Annual Portfolio Operating Expenses table is deleted in its entirety and replaced with the following:   <table style="border-collapse:collapse" border="0" cellpadding="0" cellspacing="0" width="100%"> <tr> <td width="4%"> </td> <td width="4%" valign="top" align="left">*</td> <td align="left" valign="top">MetLife Advisers, LLC has contractually agreed, for the period April 30, 2012 through April 30, 2013, to reduce the Management Fee for each Class of the Portfolio to the annual rate of 0.70% of the first $1 billion of the Portfolios average daily net assets, plus 0.65% of such assets over $1 billion up to $1.5 billion, plus 0.55% of such assets over $1.5 billion. This arrangement may be modified or discontinued prior to April 30, 2013, only with the approval of the Board of Trustees of the Portfolio. </td></tr></table> MET INVESTORS SERIES TRUST SUPPLEMENT DATED JANUARY 25, 2013 TO THE PROSPECTUS DATED APRIL 30, 2012 MFS® RESEARCH INTERNATIONAL PORTFOLIO The following changes are made to the prospectus of MFS® Research International Portfolio (the Portfolio), a series of Met Investors Series Trust. In the Portfolio Summary, the disclosure in the footnote to the Annual Portfolio Operating Expenses table is deleted in its entirety and replaced with the following:   <table style="border-collapse:collapse" border="0" cellpadding="0" cellspacing="0" width="100%"> <tr> <td width="4%"> </td> <td width="4%" valign="top" align="left">*</td> <td align="left" valign="top">MetLife Advisers, LLC has contractually agreed, for the period April 30, 2012 through April 30, 2013, to reduce the Management Fee for each Class of the Portfolio to the annual rate of 0.70% of the first $1 billion of the Portfolios average daily net assets, plus 0.65% of such assets over $1 billion up to $1.5 billion, plus 0.55% of such assets over $1.5 billion. This arrangement may be modified or discontinued prior to April 30, 2013, only with the approval of the Board of Trustees of the Portfolio. </td></tr></table> 2013-01-25