497

Sullivan & Worcester LLP	T 202 775 1200
1666 K Street, NW	F 202 293 2275
Washington, DC 20006	www.sandw.com

September 18, 2013                                                     

VIA EDGAR

EDGAR Operations Branch

Division of Investment Management

Securities and Exchange Commission

100 F Street, N.E.

Washington, DC 20549

Re:       Met Investors Series Trust (the “Trust”)

SEC File Nos. 333-48456, 811-10183

CIK - 0001126087

Ladies and Gentlemen:

Pursuant to Rule 497 under the Securities Act of 1933, as amended, enclosed is the Interactive Data File that mirrors the risk/return summary information in the supplement dated August 29, 2013 to the prospectus dated April 29, 2013 for the ClearBridge Aggressive Growth Portfolio (formerly, Legg Mason ClearBridge Aggressive Growth Portfolio), a series of the Trust, filed under Rule 497(e) on August 29, 2013 (SEC Accession No. 0001193125-13-352110).

Any questions or comments with respect to this filing may be directed to the undersigned at (202) 775-1213.

Very truly yours,

/s/ John L. Chilton

Enclosures

cc: Andrew L. Gangolf, Esq.

Michael P. Lawlor, Esq.

David C. Mahaffey, Esq.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	MET INVESTORS SERIES TRUST
Prospectus Date	rr_ProspectusDate	Apr. 29, 2013
Document Creation Date	dei_DocumentCreationDate	Aug. 29, 2013

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

MET INVESTORS SERIES TRUST

Prospectus Date

rr_ProspectusDate

Apr. 29, 2013

Supplement [Text Block]

mist_SupplementTextBlock

MET INVESTORS SERIES TRUST

SUPPLEMENT DATED AUGUST 29, 2013

TO THE

PROSPECTUS DATED APRIL 29, 2013

CLEARBRIDGE AGGRESSIVE GROWTH PORTFOLIO

(formerly, Legg Mason ClearBridge Aggressive Growth Portfolio)

The following changes to the Portfolio's Prospectus are effective November 1, 2013:

In the Portfolio Summary, the Annual Portfolio Operating Expenses table in the section entitled "Fees and Expenses of the Portfolio" is deleted in its entirety and replaced with the following:

	Class A	Class B	Class E
Management Fee	0.61%	0.61%	0.61%
Distribution and/or Service (12b-1) Fees	None	0.25%	0.15%
Other Expenses	0.03%	0.03%	0.03%
Total Annual Portfolio Operating Expenses	0.64%	0.89%	0.79%
Fee Waiver*	(0.05%)	(0.05%)	(0.05%)
Net Operating Expenses	0.59%	0.84%	0.74%

* Restated to reflect that MetLife Advisers LLC (the "Adviser") has contractually agreed, for the period from November 1, 2013 through April 30, 2014, to waive portions of the Management Fees payable to it by the Portfolio and the ClearBridge Aggressive Growth Portfolio II, another series of Met Investors Series Trust, reflecting the difference, if any, between the aggregate subadvisory fees payable by the Adviser to ClearBridge Investments, LLC ("ClearBridge") individually with respect to the Portfolio and the ClearBridge Aggressive Growth Portfolio II and the subadvisory fees that would be payable by the Adviser to ClearBridge if the assets of the Portfolio and the ClearBridge Aggressive Growth Portfolio II were aggregated for purposes of calculating such subadvisory fees. These arrangements may be modified or discontinued prior to April 30, 2014, only with the approval of the Board of Trustees of the Portfolio.

In the Portfolio Summary, the section entitled "Example" is deleted in its entirety and replaced with the following:

The following Example is intended to help you compare the cost of investing in the Portfolio with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Portfolio for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year, that the Portfolio's operating expenses remain the same and that all fee waivers for the Portfolio remain in effect through April 30, 2014. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:

	1 Year	3 Years	5 Years	10 Years
Class A	$60	$200	$353	$796
Class B	$86	$280	$490	$1,095
Class E	$76	$248	$435	$976

ClearBridge Aggressive Growth Portfolio

Risk/Return:

rr_RiskReturnAbstract

Supplement [Text Block]

mist_SupplementTextBlock

MET INVESTORS SERIES TRUST

SUPPLEMENT DATED AUGUST 29, 2013

TO THE

PROSPECTUS DATED APRIL 29, 2013

CLEARBRIDGE AGGRESSIVE GROWTH PORTFOLIO

(formerly, Legg Mason ClearBridge Aggressive Growth Portfolio)

The following changes to the Portfolio's Prospectus are effective November 1, 2013:

In the Portfolio Summary, the Annual Portfolio Operating Expenses table in the section entitled "Fees and Expenses of the Portfolio" is deleted in its entirety and replaced with the following:

	Class A	Class B	Class E
Management Fee	0.61%	0.61%	0.61%
Distribution and/or Service (12b-1) Fees	None	0.25%	0.15%
Other Expenses	0.03%	0.03%	0.03%
Total Annual Portfolio Operating Expenses	0.64%	0.89%	0.79%
Fee Waiver*	(0.05%)	(0.05%)	(0.05%)
Net Operating Expenses	0.59%	0.84%	0.74%

* Restated to reflect that MetLife Advisers LLC (the "Adviser") has contractually agreed, for the period from November 1, 2013 through April 30, 2014, to waive portions of the Management Fees payable to it by the Portfolio and the ClearBridge Aggressive Growth Portfolio II, another series of Met Investors Series Trust, reflecting the difference, if any, between the aggregate subadvisory fees payable by the Adviser to ClearBridge Investments, LLC ("ClearBridge") individually with respect to the Portfolio and the ClearBridge Aggressive Growth Portfolio II and the subadvisory fees that would be payable by the Adviser to ClearBridge if the assets of the Portfolio and the ClearBridge Aggressive Growth Portfolio II were aggregated for purposes of calculating such subadvisory fees. These arrangements may be modified or discontinued prior to April 30, 2014, only with the approval of the Board of Trustees of the Portfolio.

In the Portfolio Summary, the section entitled "Example" is deleted in its entirety and replaced with the following:

The following Example is intended to help you compare the cost of investing in the Portfolio with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Portfolio for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year, that the Portfolio's operating expenses remain the same and that all fee waivers for the Portfolio remain in effect through April 30, 2014. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:

	1 Year	3 Years	5 Years	10 Years
Class A	$60	$200	$353	$796
Class B	$86	$280	$490	$1,095
Class E	$76	$248	$435	$976

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

April 30, 2014

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following Example is intended to help you compare the cost of investing in the Portfolio with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Portfolio for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year, that the Portfolio's operating expenses remain the same and that all fee waivers for the Portfolio remain in effect through April 30, 2014. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:

ClearBridge Aggressive Growth Portfolio | Class A

Risk/Return:

rr_RiskReturnAbstract

Management Fee

rr_ManagementFeesOverAssets

0.61%

Distribution and/or Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.03%

Total Annual Portfolio Operating Expenses

rr_ExpensesOverAssets

0.64%

Fee Waiver

rr_FeeWaiverOrReimbursementOverAssets

(0.05%)

^[1]

Net Operating Expenses

rr_NetExpensesOverAssets

0.59%

1 Year

rr_ExpenseExampleYear01

$ 60

3 Years

rr_ExpenseExampleYear03

200

5 Years

rr_ExpenseExampleYear05

353

10 Years

rr_ExpenseExampleYear10

796

ClearBridge Aggressive Growth Portfolio | Class B

Risk/Return:

rr_RiskReturnAbstract

Management Fee

rr_ManagementFeesOverAssets

0.61%

Distribution and/or Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other Expenses

rr_OtherExpensesOverAssets

0.03%

Total Annual Portfolio Operating Expenses

rr_ExpensesOverAssets

0.89%

Fee Waiver

rr_FeeWaiverOrReimbursementOverAssets

(0.05%)

^[1]

Net Operating Expenses

rr_NetExpensesOverAssets

0.84%

1 Year

rr_ExpenseExampleYear01

86

3 Years

rr_ExpenseExampleYear03

280

5 Years

rr_ExpenseExampleYear05

490

10 Years

rr_ExpenseExampleYear10

1,095

ClearBridge Aggressive Growth Portfolio | Class E

Risk/Return:

rr_RiskReturnAbstract

Management Fee

rr_ManagementFeesOverAssets

0.61%

Distribution and/or Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

0.15%

Other Expenses

rr_OtherExpensesOverAssets

0.03%

Total Annual Portfolio Operating Expenses

rr_ExpensesOverAssets

0.79%

Fee Waiver

rr_FeeWaiverOrReimbursementOverAssets

(0.05%)

^[1]

Net Operating Expenses

rr_NetExpensesOverAssets

0.74%

1 Year

rr_ExpenseExampleYear01

76

3 Years

rr_ExpenseExampleYear03

248

5 Years

rr_ExpenseExampleYear05

435

10 Years

rr_ExpenseExampleYear10

$ 976

[1] Restated to reflect that MetLife Advisers LLC (the "Adviser") has contractually agreed, for the period from November 1, 2013 through April 30, 2014, to waive portions of the Management Fees payable to it by the Portfolio and the ClearBridge Aggressive Growth Portfolio II, another series of Met Investors Series Trust, reflecting the difference, if any, between the aggregate subadvisory fees payable by the Adviser to ClearBridge Investments, LLC ("ClearBridge") individually with respect to the Portfolio and the ClearBridge Aggressive Growth Portfolio II and the subadvisory fees that would be payable by the Adviser to ClearBridge if the assets of the Portfolio and the ClearBridge Aggressive Growth Portfolio II were aggregated for purposes of calculating such subadvisory fees. These arrangements may be modified or discontinued prior to April 30, 2014, only with the approval of the Board of Trustees of the Portfolio.

XML

MET INVESTORS SERIES TRUST

SUPPLEMENT DATED AUGUST 29, 2013

TO THE

PROSPECTUS DATED APRIL 29, 2013

CLEARBRIDGE AGGRESSIVE GROWTH PORTFOLIO

(formerly, Legg Mason ClearBridge Aggressive Growth Portfolio)

The following changes to the Portfolio's Prospectus are effective November 1, 2013:

In the Portfolio Summary, the Annual Portfolio Operating Expenses table in the section entitled "Fees and Expenses of the Portfolio" is deleted in its entirety and replaced with the following:

	Class A	Class B	Class E
Management Fee	0.61%	0.61%	0.61%
Distribution and/or Service (12b-1) Fees	None	0.25%	0.15%
Other Expenses	0.03%	0.03%	0.03%
Total Annual Portfolio Operating Expenses	0.64%	0.89%	0.79%
Fee Waiver*	(0.05%)	(0.05%)	(0.05%)
Net Operating Expenses	0.59%	0.84%	0.74%

* Restated to reflect that MetLife Advisers LLC (the "Adviser") has contractually agreed, for the period from November 1, 2013 through April 30, 2014, to waive portions of the Management Fees payable to it by the Portfolio and the ClearBridge Aggressive Growth Portfolio II, another series of Met Investors Series Trust, reflecting the difference, if any, between the aggregate subadvisory fees payable by the Adviser to ClearBridge Investments, LLC ("ClearBridge") individually with respect to the Portfolio and the ClearBridge Aggressive Growth Portfolio II and the subadvisory fees that would be payable by the Adviser to ClearBridge if the assets of the Portfolio and the ClearBridge Aggressive Growth Portfolio II were aggregated for purposes of calculating such subadvisory fees. These arrangements may be modified or discontinued prior to April 30, 2014, only with the approval of the Board of Trustees of the Portfolio.

In the Portfolio Summary, the section entitled "Example" is deleted in its entirety and replaced with the following:

The following Example is intended to help you compare the cost of investing in the Portfolio with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Portfolio for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year, that the Portfolio's operating expenses remain the same and that all fee waivers for the Portfolio remain in effect through April 30, 2014. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:

	1 Year	3 Years	5 Years	10 Years
Class A	$60	$200	$353	$796
Class B	$86	$280	$490	$1,095
Class E	$76	$248	$435	$976

XML

Document and Entity Information	12 Months Ended
	Apr. 29, 2013
Risk/Return:
Document Type	Other
Document Period End Date	Dec. 31, 2012
Registrant Name	MET INVESTORS SERIES TRUST
Central Index Key	0001126087
Amendment Flag	false
Document Creation Date	Aug. 29, 2013
Document Effective Date	Aug. 29, 2013
Prospectus Date	Apr. 29, 2013