Q3 | 16 Investment Update

MFS® GLOBAL HIGH YIELD FUND Seeking a high level of current income from global high yield bonds Seeks total return with an emphasis on a high current income but also considering capital appreciation by investing in lower quality bonds from around the world. Management focuses on bonds issued globally by companies our analysts believe have solid or improving credit fundamentals. Management allocates across a variety of high-yield industries and issuers. Benchmark: BofA Merrill Lynch Global High Yield Constrained Index (USD hedged).

Fund objective Seeks total return with an emphasis on high current income, but also considering capital appreciation.

Key performance points MFS Global High Yield Fund – I underperformed the BofA Merrill Lynch Global High Yield - Constrained Index (USD hedged) during the third quarter of 2016 with a return of 4.47% versus 5.21% for the benchmark. 

Detractors versus BofA ML Global High Yield Constrained (USD hedged) Index  Allocation and selection within the United States  Underweight Emerging Markets

Contributors versus BofA ML Global High Yield Constrained (USD hedged) Index  Underweight to and selection within Europe  Selection within Emerging Markets Significant impacts on performance – Detractors Allocation and selection within the United States An underweight to CCC-rated securities, as well as selection within healthcare in the United States, marginally detracted from performance during the quarter. Underweight to Emerging Markets The portfolio's underweight to emerging markets detracted from performance as the region outperformed the benchmark during the quarter.

Significant impacts on performance – Contributors Underweight to and selection within Europe An underweight to and selection within Europe both contributed to performance as the region underperformed the broader index. Selection within the capital goods sector also contributed to relative performance in the region.

NOT FDIC INSURED  MAY LOSE VALUE  NO BANK GUARANTEE

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Q3 | 16

Investment Update

MFS Global High Yield Fund

Selection within Emerging Markets Selection across several industries contributed to relative performance within the region with no single industry having an outsized effect during the quarter.

Fixed income outlook and positioning Global sovereign yields generally rose slightly during the quarter as market concerns about the impact of Brexit eased. Stable economic growth, as well as discussions by policymakers around the timeline of continued accommodation, also contributed to yields moving slightly higher. In particular, while the Fed kept short-term rates steady during the quarter, officials indicated that the U.S. economy was on solidenough footing to warrant an increase in short-term rates by the end of this year. In our view, the lower-forlonger interest rate environment is expected to persist for some time as global liquidity remains abundant, limiting backups in yield and flattening yield curves. In that backdrop, credit assets registered another strong quarter. The key outperformers in this midFebruary onwards rally continued to assert themselves, reinforcing the narrowness of market performance. Supported by firming oil prices, an improving outlook for defaults, and continued global central bank dovishness, commodity-related sectors and the lower quality tiers outperformed. With energy and basic industries again outperforming by a significant margin, these two sectors roughly doubled the return of the broader investment grade and high yield indices on a year-to-date basis. Still, while the market remained focused on commodity-related issuers and beta, all corporate industries in the investment grade and high yield U.S. indices recorded positive absolute returns in the third quarter. As might be expected in a commodity-driven rally, the U.S. and emerging markets high yield outperformed Europe. Investment grade and high yield new issuance was robust in September. Demand sopped up the new supply as investors continued to seek yield, driving down new issue concessions. Supportive of high yield fundamentals, approximately 70% of September's new issue volume was earmarked for refinancing existing debt (source: BofA ML). The pace of high yield new issuance YTD ended September less than 10% lower than last year, even accounting for a slow first few months of the year. The U.S. default rate ended September at less than 5% and only 0.5% excluding commodities (source: JP Morgan). Globally, the amount of high yield debt upgraded doubled the amount of debt downgraded in September (source: BofA ML), and the default rate is expected to continue to decline to near long-term averages by the end of this year (source: JP Morgan). Given the positive environment for risk taking and slight increase in U.S. treasury yields, high yield outperformed investment grade on an absolute and excess return basis. Performance within the quality tiers was also consistent with expectations as BB's outperformed investment grade but lagged the riskier segments of the high yield market. Strong performance continued through the third quarter as the YTD return for global high yield reached 14% (return based on BofA ML Global High Yield Constrained index). With the rally, spreads are now at or near long-term averages and valuations generally reflect a positive outlook for high yield fundamentals in our view. Our indicators of value, including a proprietary spread decomposition model and measures of dispersion and loss-adjusted spreads, signal that the attractive opportunity presented to high yield investors earlier in the year has largely evaporated. Consistent with tightening spreads and reduced opportunity, the portfolio management team increased the quality of the portfolio during the quarter, continuing a trend that began towards the end of the second quarter. The portfolio moved from a roughly neutral weight in CCC's to a modest underweight at the end of the quarter, while the BB underweight was trimmed fairly significantly^. Page 2 of 5

Q3 | 16

Investment Update

MFS Global High Yield Fund

At the sector level, the largest increase in weight was in the energy sector, the result of market appreciation and purchases mainly within the midstream and independent exploration and production industries. As a result, the portfolio's relative underweight to the sector was reduced by half. Midstream remained the largest overweight within the energy sector as we continue to favor these volume-based businesses. We've become more positive on higher quality independent E&P issuers as industry default rates are expected to fall to historical averages and companies have improved their balance sheets. The other meaningful increase to sector exposures was in capital goods, by a wide margin the portfolio's largest sector overweight. Driving that overweight were exposures in the building materials, diversified manufacturing, and packaging industries. The key sector underweights at the end of the quarter were banking (mainly emerging market banks), consumer cyclicals, technology, and basic industry. The consumer cyclicals position was largely driven by an underweight to home construction, a capital intensive business with poor through-cycle fundamentals. We were underweight and selective with technology companies, seeking to avoid shorter-cycle businesses exposed to product disruption or changing consumer preferences. Within basic industry, the portfolio was underweight metals & mining but overweight chemicals companies experiencing positive cyclical dynamics. Regionally, we believe the U.S. offers the most attractive opportunities given fundamentals and economic/political backdrop. Fundamentals are reasonably healthy outside of weaker energy and metals & mining credits and spreads are generally more attractive than those in Europe. Europe's political environment also appears uncertain, as the Brexit vote has recently shown. In emerging markets, yields are relatively attractive and political outcomes have become more market friendly. Still, the commodity environment remains a source of fundamental weakness. We added to our U.S. and European exposures and trimmed EM during the quarter. As spreads continued to tighten to levels near or through long-term averages and a positive outlook is largely priced in, the team moved to a higher quality portfolio. If spreads stay on a tightening track, we'll remain biased to quality in order to buffer the portfolio from potential volatility while being prepared to take advantage of new opportunities as they emerge. Given our view that valuations have tightened considerably over the last several months, the portfolio has continued to trim risk. Our risk budgeting process seeks to assess value throughout the cycle and, often in the late stages of a high yield rally, spreads, while still offering value in better quality companies, have become rich among the lowest quality tiers. With buying liquidity abundant, we are sellers of what we view are the more vulnerable credits in the portfolio. We believe it is important to reposition the portfolio early, prior to a risk-off inflection point, to take advantage of liquidity in the market. While being under-risked relative to the index may result in modest short-term underperformance, we encourage clients to look longer term and towards the goal of enhancing return and mitigating volatility over a cycle for the strategic investor. In this current period, in general the portfolio's lack of exposure to the lowest quality tiers detracted as did any exposure to residual cash as high yield markets rallied strongly. While selection in certain sectors detracted, broadly it was our preference to own companies positioned to perform well through-cycle in more-stable industries that appealed less to the market over the three-month period.

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Q3 | 16

Investment Update

MFS Global High Yield Fund

Performance review as of 09/30/16 Portfolio %

Q3 2016

1 Year

3 Years

5 Years

10 Years

4.41 -0.02 4.47 4.46

10.12 5.44 10.58 10.38

4.16 2.66 4.42 4.32

7.06 6.14 7.33 7.43

5.71 5.25 5.97 6.04

5.21

13.51

5.89

9.11

8.10

4.65

9.32

3.78

7.05

6.19

Class A

Class I

Class R4

Gross Expense Ratio

1.15

0.90

0.90

Net Expense Ratio

1.07

0.82

0.82

Class A without sales charge Class A with 4.25% maximum sales charge Class I Class R4 BofA Merrill Lynch Global High Yield - Constrained Index (USD hedged) Lipper High Yield Cat. Avg. Fund Expenses

Gross expense ratio is the fund's total operating expense ratio from the fund's most recent prospectus. Net expense ratio reflects the reduction of expenses from fee waivers, reimbursements, and the exclusion of interest and fees. Elimination of these reductions will result in higher expenses and lower performance. These reductions will continue until at least May 31, 2017.

Performance data shown represents past performance and are no guarantee of future results. Investment return and principal value fluctuate so your shares, when sold, may be worth more or less than the original cost; current performance may be lower or higher than quoted. For most recent month-end performance, please visit mfs.com. Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund's performance results would be less favorable. All results assume the reinvestment of dividends and capital gains. The performance is as of the date shown; it may not include the fund's entire investment portfolio and is subject to change. Performance for Class R shares includes the performance of the fund’s Class I shares, adjusted to take into account differences in sales loads and class-specific operating expenses (such as Rule 12b-1 fees), if any, for periods prior to their offering. Please see the prospectus for additional information about performance and expenses. Sales Charges Class I shares ("I") have no sales charge or Rule 12b-1 fees and are available only to eligible investors. Class R4 shares ("R4") have no initial sales charge or CDSC. Shares are available only to certain retirement plans. The BofA Merrill Lynch Global High Yield - Constrained Index (USD hedged) contains all securities in the BofA Merrill Lynch Global High Yield (USD hedged) Index but caps issuer exposure at 2%. Index returns do not take into account investment-related fees and expenses. It is not possible to invest directly in an index.

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Q3 | 16

Investment Update

MFS Global High Yield Fund

Important risk considerations The fund may not achieve its objective and/or you could lose money on your investment in the fund. Investments in debt instruments may decline in value as the result of declines in the credit quality of the issuer, borrower, counterparty, or other entity responsible for payment, underlying collateral, or changes in economic, political, issuer-specific, or other conditions. Certain types of debt instruments can be more sensitive to these factors and therefore more volatile. In addition, debt instruments entail interest rate risk (as interest rates rise, prices usually fall), therefore the Fund's share price may decline during rising rates. Funds that consist of debt instruments with longer durations are generally more sensitive to a rise in interest rates than those with shorter durations. At times, and particularly during periods of market turmoil, all or a large portion of segments of the market may not have an active trading market. As a result, it may be difficult to value these investments and it may not be possible to sell a particular investment or type of investment at any particular time or at an acceptable price. The price of an instrument trading at a negative interest rate responds to interest rate changes like other debt instruments; however, an instrument purchased at a negative interest rate is expected to produce a negative return if held to maturity. Investments in foreign markets can involve greater risk and volatility than U.S. investments because of adverse market, currency, economic, industry, political, regulatory, geopolitical, or other conditions. Emerging markets can have less market structure, depth, and regulatory, custodial or operational oversight and greater political, social, and economic instability than developed markets. Investments in derivatives can be used to take both long and short positions, be highly volatile, involve leverage (which can magnify losses), and involve risks in addition to the risks of the underlying indicator(s) on which the derivative is based, such as counterparty and liquidity risk. Investments in below investment grade quality debt instruments can be more volatile and have greater risk of default, or already be in default, than higher-quality debt instruments. Please see the prospectus for further information on these and other risk considerations. This portfolio is actively managed, and current holdings may be different. ^For all securities other than those specifically described below, ratings are assigned to underlying securities utilizing ratings from Moody's, Fitch, and Standard & Poor's rating agencies and applying the following hierarchy: If all three agencies provide a rating, the middle rating (after dropping the highest and lowest ratings) is assigned; if two of the three agencies rate a security, the lower of the two is assigned. Ratings are shown in the S&P and Fitch scale (e.g., AAA). All ratings are subject to change. U.S. Government includes securities issued by the U.S. Department of the Treasury. Federal Agencies includes rated and unrated U.S. Agency fixed-income securities, U.S. Agency MBS, and CMOs of U.S. Agency MBS. Other Not Rated includes fixed income securities which have not been rated by any rating agency. The portfolio itself has not been rated. The views expressed are those of MFS and are subject to change at any time. These views should not be relied upon as investment advice, as securities recommendations, or as an indication of trading intent on behalf of any other MFS investment product. No forecasts can be guaranteed.

Before investing, consider the fund's investment objectives, risks, charges, and expenses. For a prospectus, or summary prospectus, containing this and other information, contact your investment professional or view online at mfs.com. Please read it carefully. MFS® investment products are offered through MFS Fund Distributors, Inc., 111 Huntington Avenue, Boston, MA 02199. 10881.41

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