MFS International Diversification Fund

MFS International Diversification Fund Summary of Key Information

Investment Objective

The fund’s investment objective is to seek capital appreciation.

Fees and Expenses

This table describes the fees and expenses that you may pay when you buy and hold shares of the fund. Investors may also pay commissions or other fees to their financial intermediaries when they buy and hold shares of the fund, which are not reflected below.

You may qualify for sales charge reductions if, with respect to Class A shares, you and certain members of your family invest, or agree to invest in the future, at least $50,000 in MFS funds. More information about these and other waivers and reductions is available from your financial intermediary and in “Sales Charges and Waivers and Reductions” on page 11 and “Appendix A — Waivers and Reductions of Sales Charges” on page A-1 of the fund’s prospectus.

Shareholder Fees (fees paid directly from your investment):

Shareholder Fees - MFS International Diversification Fund	A		B	C	I	R1	R2	R3	R4	R6
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	5.75%		none	none	none	none	none	none	none	none
Maximum Deferred Sales Charge (Load) (as a percentage of original purchase price or redemption proceeds, whichever is less)	1.00%	[1]	4.00%	1.00%	none	none	none	none	none	none

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

Annual Fund Operating Expenses - MFS International Diversification Fund		A	B	C	I	R1	R2	R3	R4	R6
Management Fee		none	none	none	none	none	none	none	none	none
Distribution and/or Service (12b-1) Fees		0.25%	1.00%	1.00%	none	1.00%	0.50%	0.25%	none	none
Other Expenses		0.12%	0.12%	0.12%	0.12%	0.12%	0.12%	0.12%	0.12%	0.02%
Acquired (Underlying) Fund Fees and Expenses		0.75%	0.75%	0.75%	0.75%	0.75%	0.75%	0.75%	0.75%	0.75%
Total Annual Fund Operating Expenses		1.12%	1.87%	1.87%	0.87%	1.87%	1.37%	1.12%	0.87%	0.77%
Fee Reductions and/or Expense Reimbursements	[1]	(0.02%)	(0.02%)	(0.02%)	(0.02%)	(0.02%)	(0.02%)	(0.02%)	(0.02%)	(0.02%)
Total Annual Fund Operating Expenses After Fee Reductions and/or Expense Reimbursements		1.10%	1.85%	1.85%	0.85%	1.85%	1.35%	1.10%	0.85%	0.75%

Example

This example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds.

The example assumes that: you invest $10,000 in the fund for the time periods indicated and you redeem your shares at the end of the time periods (unless otherwise indicated); your investment has a 5% return each year; and the fund’s operating expenses remain the same.

Although your actual costs will likely be higher or lower, under these assumptions your costs would be:

Expense Example - MFS International Diversification Fund - USD ($)	1 YEAR	3 YEARS	5 YEARS	10 YEARS
A	681	909	1,155	1,858
B	588	886	1,209	1,993
C	288	586	1,009	2,189
I	87	276	480	1,071
R1	188	586	1,009	2,189
R2	137	432	748	1,645
R3	112	354	615	1,361
R4	87	276	480	1,071
R6	77	244	426	952

Expense Example No Redemption - MFS International Diversification Fund - USD ($)	1 YEAR	3 YEARS	5 YEARS	10 YEARS
B	188	586	1,009	1,993
C	188	586	1,009	2,189

Portfolio Turnover

The fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when shares are held in a taxable account. These transaction costs, which are not reflected in “Annual Fund Operating Expenses” or in the “Example,” affect the fund’s performance.  During the most recent fiscal year, the fund’s portfolio turnover rate was 6% of the average value of its portfolio.

Principal Investment Strategies

The fund is designed to provide diversification within the international asset class by investing the majority of its assets in other mutual funds advised by MFS (Massachusetts Financial Services Company, the fund’s investment adviser), referred to as underlying funds. The underlying funds are selected based on underlying fund classifications, historical risk, performance, and other factors. MFS seeks to diversify the fund’s investments in terms of market capitalization (by including large, mid, and/or small cap underlying funds), by style (by including both growth and value underlying funds), and by geography (by including developed and emerging market underlying funds).  MFS normally invests each underlying fund’s assets across different industries, sectors, countries, and regions, but MFS may invest a significant percentage of an underlying fund’s assets in issuers in a single industry, sector, country, or region.

The Board of Trustees of the fund has approved modifications to the underlying fund target weightings of the fund. The transition to the revised underlying fund allocations commenced on or about June 30, 2020, and will be completed by December 31, 2020,  

although these dates could change based on market conditions and other factors.

As of June 30, 2020, the fund’s target allocation among underlying funds was:

MFS Emerging Markets Equity Fund	15	%
MFS International Growth Fund	22.5	%
MFS International Intrinsic Value Fund	22.5	%
MFS International New Discovery Fund	10	%
MFS Research International Fund	30	%

As of December 31, 2020, the fund’s target allocation among underlying funds is expected to be:

MFS Emerging Markets Equity Fund	17.5	%
MFS International Growth Fund	15	%
MFS International Intrinsic Value Fund	15	%
MFS International Large Cap Value Fund	15	%
MFS International New Discovery Fund	10	%
MFS Research International Fund	27.5	%

Principal Risks

As with any mutual fund, the fund may not achieve its objective and/or you could lose money on your investment in the fund. An investment in the fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency.

The principal risks of investing in the fund are:

Allocation Risk:  MFS’ assessment of the risk/return potential of asset classes and underlying funds, and the resulting allocation among asset classes and underlying funds, may not produce the intended results and/or can lead to an investment focus that results in the fund underperforming other funds with similar investment strategies and/or underperforming the markets in which the fund invests.

Underlying Funds Risk:  MFS’ strategy of investing in underlying funds exposes the fund to the risks of the underlying funds. Each underlying fund pursues its own investment objective and strategies and may not achieve its objective.  In addition, shareholders of the fund will indirectly bear the fees and expenses of the underlying funds.

Investment Selection Risk:  MFS’ investment analysis and its selection of investments may not produce the intended results and/or can lead to an investment focus that results in the fund underperforming other funds with similar investment strategies and/or underperforming the markets in which the fund invests.

Equity Market Risk/Company Risk:  Equity markets are volatile and can decline significantly in response to, or investor perceptions of, issuer, market, economic, industry, political, regulatory, geopolitical, environmental, public health, and other conditions.  These conditions can affect a single issuer or type of security, issuers within a broad market sector, industry or geographic region, or the equity markets in general.  Certain events can have a dramatic adverse effect on equity markets and may lead to periods of high volatility in an equity market or a segment of an equity market.

Growth Company Risk:  The stocks of growth companies can be more sensitive to the company’s earnings and more volatile than the market in general.

Value Company Risk:  The stocks of value companies can continue to be undervalued for long periods of time and not realize their expected value and can be more volatile than the market in general.

Intrinsic Value Strategy Risk:  The stocks of companies that MFS believes are undervalued compared to their intrinsic value can continue to be undervalued for long periods of time, may not realize their expected value, and can be volatile.

Focus Risk:  Issuers in a single industry, sector, country, or region can react similarly to market, currency, political, economic, regulatory, geopolitical, environmental, public health, and other conditions, and the fund’s performance will be affected by the conditions in the industries, sectors, countries and regions to which the fund is exposed.

Foreign Risk:  Exposure to foreign markets through issuers or currencies can involve additional risks relating to market, economic, industry, political, regulatory, geopolitical, environmental, public health, and other conditions. These factors can make foreign investments, especially those tied economically to emerging markets, more volatile and less liquid than U.S. investments. In addition, foreign markets can react differently to these conditions than the U.S. market.

Emerging Markets Risk:  Investments tied economically to emerging markets, especially frontier markets, can involve additional and greater risks than the risks associated with investments in developed foreign markets.  Emerging markets can have less developed markets, greater custody and operational risk, less developed legal, regulatory, and accounting systems, and greater political, social, geopolitical, and economic instability than developed markets.

Currency Risk:  The value of foreign currencies relative to the U.S. dollar fluctuates in response to market, economic, industry, political, regulatory, geopolitical, environmental, public health, and other conditions, and changes in currency exchange rates impact the financial condition of companies or other issuers and may change the value in U.S. dollars of investments denominated in foreign currencies.

Derivatives Risk:  Derivatives can be highly volatile and involve risks in addition to the risks of the underlying indicator(s) on which the derivative is based. Gains or losses from derivatives can be substantially greater than the derivatives’ original cost.  Derivatives can involve leverage.

Leveraging Risk:  Leverage involves investment exposure in an amount exceeding the initial investment. Leverage can cause increased volatility by magnifying gains or losses.

Counterparty and Third Party Risk:  Transactions involving a counterparty or third party other than the issuer of the instrument are subject to the credit risk of the counterparty or third party, and to the counterparty’s or third party’s ability or willingness to perform in accordance with the terms of the transaction.

Liquidity Risk:  It may be difficult to value, and it may not be possible to sell, certain investments, types of investments, and/or investments in certain segments of the market, and the fund may have to sell certain of these investments at prices or times that are not advantageous in order to meet redemptions or other cash needs.

Large Shareholder Risk: From time to time, shareholders of the fund (which may include institutional investors, financial intermediaries, or other MFS funds) may make relatively large redemptions or purchases of fund shares.  These transactions may cause the fund to sell securities or invest additional cash, as the case may be, at disadvantageous prices.  Redemptions of a large number of shares also may increase transaction costs or have adverse tax consequences for shareholders of the fund by requiring a sale of portfolio securities.

Performance Information

The bar chart and performance table below are intended to provide some indication of the risks of investing in the fund by showing changes in the fund’s performance over time and how the fund’s performance over time compares with that of a broad measure of market performance.

The fund’s past performance (before and after taxes) does not necessarily indicate how the fund will perform in the future. Updated performance is available online at mfs.com or by calling 1-800-225-2606.

The bar chart does not take into account any sales charges (loads) that you may be required to pay upon purchase or redemption of the fund’s shares. If these sales charges were included, they would reduce the returns shown.

Class A Bar Chart. 

The total return for the six-month period ended June 30, 2020, was (6.14)%. During the period(s) shown in the bar chart, the highest quarterly return was 15.46% (for the calendar quarter ended September 30, 2010) and the lowest quarterly return was (17.71)% (for the calendar quarter ended September 30, 2011).

Performance Table.

Average Annual Total Returns (For the Periods Ended December 31, 2019)

Average Annual Returns - MFS International Diversification Fund	Average Annual Returns, 1 Year	Average Annual Returns, 5 Years	Average Annual Returns, 10 Years
B	20.74%	7.03%	6.59%
C	23.73%	7.33%	6.44%
I	26.00%	8.42%	7.51%
R1	24.75%	7.34%	6.44%
R2	25.32%	7.87%	6.96%
R3	25.66%	8.13%	7.23%
R4	26.02%	8.41%	7.51%
R6	26.09%	8.46%	7.53%
A	18.45%	6.87%	6.60%
After Taxes on Distributions | A	17.90%	6.46%	6.34%
After Taxes on Distributions and Sale of Fund Shares | A	11.46%	5.42%	5.37%
MSCI All Country World (ex-US) Index (net div)	21.51%	5.51%	4.97%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Your actual after-tax returns will depend on your own tax situation, and may differ from those shown. The after-tax returns shown are not relevant to investors who hold their shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. The after-tax returns are shown for only one of the fund’s classes of shares, and after-tax returns for the fund’s other classes of shares will vary from the returns shown.

[1] This contingent deferred sales charge (CDSC) applies to shares purchased without an initial sales charge and redeemed within 18 months of purchase.

[1] Massachusetts Financial Services Company has agreed in writing to bear the fund’s expenses, excluding management fees, distribution and service fees, interest, taxes, extraordinary expenses, brokerage and transaction costs, investment-related expenses, and fees and expenses associated with investments in investment companies and other similar investment vehicles, such that “Other Expenses” do not exceed 0.10% of the class’ average daily net assets annually for each of Class A, Class B, Class C, Class I, Class R1, Class R2, Class R3, and Class R4 shares, and 0.00% of the class’ average daily net assets annually for Class R6 shares. This written agreement will continue until modified by the fund’s Board of Trustees, but such agreement will continue until at least September 30, 2021.