Incorporated herein by reference is a supplement to the prospectus of MFS Strategic Income Series, a series of MFS Variable Insurance Trust (File No. 033-74668), filed pursuant to Rule 497(e) under the Securities Act of 1933, as amended, on February 28, 2013 (SEC Accession No. 0000912938-13-000152).
| MFS Strategic Income Series | MFS Strategic Income Series |
| MFS Strategic Income Series |
Effective immediately, the sub-section entitled "Principal Investment Strategies" beneath the main heading "Summary of Key Information" is restated in its entirety as follows: |
| Principal Investment Strategies |
MFS (Massachusetts Financial Services Company, the fund's investment adviser) normally invests the fund’s assets primarily in debt instruments. MFS may invest the fund's assets in other mutual funds advised by MFS that invest in securities instead of investing directly in such securities. MFS normally invests the fund’s assets in U.S. Government securities, foreign government securities, mortgage-backed and other asset-backed securities of U.S. and foreign issuers, corporate bonds of U.S. and/or foreign issuers, and/or debt instruments of issuers located in emerging market countries. MFS allocates the fund’s assets across these categories with a view toward broad diversification across and within these categories. MFS may also invest the fund’s assets in equity securities. MFS may invest up to 100% of the fund’s assets directly or indirectly in less than investment grade quality debt instruments (lower quality debt instruments). MFS may invest a large percentage of the fund’s assets in issuers in a single country, a small number of countries, or a particular geographic region. While MFS may use derivatives for any investment purpose, to the extent MFS uses derivatives, MFS expects to use derivatives primarily to increase or decrease exposure to a particular market, segment of the market, or security, to increase or decrease interest rate or currency exposure, or as alternatives to direct investments. Derivatives include futures, forward contracts, options, structured securities, inverse floating rate instruments, and swaps. MFS uses a bottom-up investment approach to buying and selling investments for the fund. Investments are selected primarily based on fundamental analysis of individual issuers and instruments. Quantitative models that systematically evaluate issuers and instruments may also be considered. |
"+ text.join( "
\n" ) +"
" + text[p] + "
\n"; } } }else{ formatted = '' + raw + '
'; } html = ''+ "\n"+''+ "\n"+'| '+ "\n"+' formatted: '+ ( this.Default == 'raw' ? 'as Filed' : 'with Text Wrapped' ) +''+ "\n"+' | '+ "\n"+'
| '+ "\n"+' '+ "\n"+' | '+ "\n"+'
| '+ "\n"+' '+ "\n"+' | '+ "\n"+'
| Label | Element | Value |
|---|---|---|
|
MFS Strategic Income Series | MFS Strategic Income Series
|
||
| Risk/Return: | rr_RiskReturnAbstract | |
| Supplement [Text Block] | ck0000918571_SupplementTextBlock | Effective immediately, the sub-section entitled "Principal Investment Strategies" beneath the main heading "Summary of Key Information" is restated in its entirety as follows: |
| Risk/Return [Heading] | rr_RiskReturnHeading | MFS Strategic Income Series |
| Strategy [Heading] | rr_StrategyHeading | Principal Investment Strategies |
| Strategy Narrative [Text Block] | rr_StrategyNarrativeTextBlock | MFS (Massachusetts Financial Services Company, the fund's investment adviser) normally invests the fund’s assets primarily in debt instruments. MFS may invest the fund's assets in other mutual funds advised by MFS that invest in securities instead of investing directly in such securities. MFS normally invests the fund’s assets in U.S. Government securities, foreign government securities, mortgage-backed and other asset-backed securities of U.S. and foreign issuers, corporate bonds of U.S. and/or foreign issuers, and/or debt instruments of issuers located in emerging market countries. MFS allocates the fund’s assets across these categories with a view toward broad diversification across and within these categories. MFS may also invest the fund’s assets in equity securities. MFS may invest up to 100% of the fund’s assets directly or indirectly in less than investment grade quality debt instruments (lower quality debt instruments). MFS may invest a large percentage of the fund’s assets in issuers in a single country, a small number of countries, or a particular geographic region. While MFS may use derivatives for any investment purpose, to the extent MFS uses derivatives, MFS expects to use derivatives primarily to increase or decrease exposure to a particular market, segment of the market, or security, to increase or decrease interest rate or currency exposure, or as alternatives to direct investments. Derivatives include futures, forward contracts, options, structured securities, inverse floating rate instruments, and swaps. MFS uses a bottom-up investment approach to buying and selling investments for the fund. Investments are selected primarily based on fundamental analysis of individual issuers and instruments. Quantitative models that systematically evaluate issuers and instruments may also be considered. |
|
Document and Entity Information
|
0 Months Ended |
|---|---|
|
Feb. 28, 2013
|
|
| Risk/Return: | |
| Document Type | Other |
| Document Period End Date | Feb. 28, 2013 |
| Registrant Name | MFS VARIABLE INSURANCE TRUST |
| Central Index Key | 0000918571 |
| Amendment Flag | false |
| Document Creation Date | Feb. 28, 2013 |
| Document Effective Date | Feb. 28, 2013 |
| Prospectus Date | Apr. 29, 2012 |
| Label | Element | Value |
|---|---|---|
| Risk/Return: | rr_RiskReturnAbstract | |
| Prospectus Date | rr_ProspectusDate | Apr. 29, 2012 |