Fund MSCI EAFE Index

Sector Weightings: Defines what % of each sector this fund holdscompared to its benchmark listed here.

QTD YTD

Sector Attribution: Describes how sector weighting decisions affectedreturns by sector.

Sector Attribution Details:Sector Fund Weight Q T D Y T D

Communication Services 6.40 -0.65 -1.24

Consumer Discretionary 12.33 -0.03 -0.80

Consumer Staples 12.45 0.28 0.63

Energy 2.21 0.02 -0.42

Financials 20.34 -0.02 -0.43

Health Care 12.28 0.27 -0.33

Industrials 14.34 -0.29 0.12

Information Technology 8.16 -0.12 1.11

Materials 7.49 0.42 0.44

Real Estate 0.00 -0.25 -0.13

Utilities 0.68 -0.33 -0.47

Cash 1.41 0.15 0.27

Tota l 9 8 . 0 8 -0.53 - 1 . 2 4

Quarterly Portfolio Commentary:

Phil Connor, CFA Investment DirectorInvestment Experience: 28 Years

HIGHLIGHTS • Global stocks ended the quarter ahead of domestic equities, but bothclosed the year in negative territory.• Stock selection was the primary reason for Fund underperformance.• The communication services sector was a particularly weak area for theFund in the quarter and year.• Country weightings attributed limited impact on results in the quarterand year.

Fund Objective: The Fund seeks growth of capital over the long-term by investing in foreign equity securities.

These materials and the platform of investments made available by MassMutual are offered without regard to the individualized needs of any plan, itsparticipants, or beneficiaries. These materials are not intended as impartial investment advice or to give advice in a fiduciary capacity to any plan.

NOT FDIC INSURED MAY LOSE VALUE NO BANK GUARANTEE

Quarterly Review

R5 SHARE CLASS TICKER: MOSSX

As of 12/31/2018

MassMutual Select Overseas FundMassachusetts Financial Services Company | Harris Associates L.P.

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*Sector Weighting may not add to 100% due to securities that are not classified according to a specific sector.

Quarterly Portfolio Commentary

Concerns over the ongoing trade war with China, stalling global growth, and the Federal Reserve’s continued push toward less accommodative monetarypolicy drove investors to flee riskier equity asset classes in the last quarter of the year. Global stocks ended the quarter ahead of domestic equities, butboth closed the year in negative territory. The MSCI EAFE Index modestly lagged active management for the quarter. Broad-based performance weaknessaffected all eleven benchmark sectors. From a style perspective, value stocks outperformed growth stocks across the market cap spectrum for the quarter.At the sector level, the energy, information technology, and materials sectors posted the weakest results. The financial sector also struggled and, given itssizable weight in the index, had the greatest impact on overall performance. From a country perspective, Austria underperformed all others, but given itspaltry weight in the index, the country had little impact on overall results. Japan, which is the largest country weight at approximately 23%, detractedmost from the benchmark’s quarterly results. As the world's second largest stock market, Japan struggled in 2018 due to concerns about trade wars and theimpact of a planned countrywide sales tax increase. In addition, strong domestic corporate earnings continue to lure U.S. investors away from foreigninvestment.

Stock selection in the communication services sector was the primary driver of underperformance compared to the benchmark for the quarter. Thesector comprises two industry groups - media & entertainment and telecommunication service. The former delivered much weaker results than did thelatter. The sector’s return held up modestly better than the benchmark and delivered some positive attribution. The Fund has a slight overweight to thesector. However, the Fund’s holdings in this sector are entirely in the media & entertainment industries, which underperformed and affected relativeperformance for the quarter. The Fund’s sector exposure is diversified across eight holdings. Three of holdings - WPP PLC, Baidu Inc. ADR, and LibertyGlobal PLC - were primary detractors due to their higher relative weights. Each company has its own fundamental circumstances, but together theysuccumbed to deeper negative sentiment about cyclical outlooks for advertising revenue. Weakness in the same group of stocks also detracted fromrelative performance for the year.

The sentiment on cyclicality was also evident in two Fund holdings within the transportation industry of the industrials sector during the quarter. BothRyanair Holdings PLC ADR and Canadian National Railway Co. saw large price drops compared to the transportation industry as a whole. The capital goodsindustry was also among the weakest performing areas of benchmark. The Fund’s exposure here also resulted in a large detraction from performance. Forthe year, however, the industrials sector was a small source of value add relative to the benchmark. Other sources of detraction in the quarter came fromselection in the energy and consumer discretionary sectors – particularly autos and retailing. Allocation effects from underweight to the utilities and realestate sectors, which displayed defensiveness in the down market environment also detracted.

Performance impact from the financial sector was about neutral for the quarter, but two holdings in the sector were among the Fund’s top five overalldetractors. Banking firm BNP Paribas and diversified financial Credit Suisse Group AG not only detracted for the quarter, but for the year. However,overall negative impact from the financial sector was less than impact from other sectors. Banks showed particular weakness for the year, even though theFund had positive attribution from the industry. Weak performance in diversified financials offset these gains. For the year, selection in the automobiles &components industry caused the consumer discretionary sector to become the second-leading source of sector detraction. The stocks of a handful ofsuch companies fell sharply which was seen as a reaction to concerns about trade, peak sales, and new European emissions protocols.

TICKER: MOSSX Inception: 5/1/2001Morningstar Category: Foreign Large Blend

Average Annual Total Return

Q T D Y T D 1 Year 3 Year 5 Year 10 year

MassMutual Select Overseas R5 -13.37% -16.20% -16.20% 2.95% -0.05% 7.43%

MSCI EAFE Index -12.54% -13.79% -13.79% 2.87% 0.53% 6.32%

Category Average Return -- -- -14.59% 2.63% 0.10% 5.89%

Category Rank -- -- 73 47 57 12

# of Funds in Category -- -- 741 639 508 380

Performance shown is for class R5 shares. Gross expenses = 1.03%, Net expense = 1.03%. Current performance may be higher or lower. Max Sales chargefor R5 is 0%Performance shown is past performance. Past performance does not guarantee future results . You can lose money, includingloss of pr incipal , by invest ing in this fund. Investors should careful ly consider investment objectives, r isks , charges andexpenses. This and other important information is contained in the fund prospectuses and summary prospectuses, which can beobtained from www.massmutualfunds.com and should be read careful ly before invest ing. A l ist of the Fund’s holdings can alsobe obtained from www.massmutualfunds.com. Current performance may be lower or higher than return data quoted herein. Formore current information, including month-end performance, please cal l 1-866-444-2601.Investment Risks - The Fund’s Princ ipa l R isks include-Cash Position Risk, Convertible Securities Risk, Derivatives Risk, Equity Securities Risk, ForeignInvestment Risk; Emerging Markets Risk; Currency Risk, Geographic Focus Risk, Growth Company Risk, Large Company Risk, Liquidity Risk, ManagementRisk, Market Risk, Preferred Stock Risk, Sector Risk, Small and Mid-Cap Company Risk, Valuation Risk, and Value Company Risk. Please refer to thesummary prospectus (a copy can be obtained by sending an email to fundinfo@massmutual.com) for more information on the specific risks.You cannot invest directly in an index. The Morningstar percenti le ranking is based on the fund’s total-return percenti le rank relat iveto al l funds that have the same category for the same t ime period. The highest (or most favorable) percentile rank is 1%, and the lowest (orleast favorable) percentile rank is 100%. Morningstar total return includes both income and capital gains or losses and is not adjusted for sales charges. ©2019 Morningstar, Inc. All Rights Reserved. The information contained herein: (1) is proprietary to Morningstar and/or its content providers; (2) may not becopied or distributed; and (3) is not warranted to be accurate, complete or timely. Neither Morningstar nor its content providers are responsible for anydamages or losses arising from any use of this information.

MassMutual Select Overseas Fund

Quarter to Date:

Top 5 Contributors F u n dW e i g h t

AbsoluteReturn*

Portfol ioContr ibut ion

PT Bank Mandiri (Persero)Tbk 0.74 13.64 0.10

Housing DevelopmentFinance Corp Ltd 0.59 16.49 0.08

Willis Towers Watson PLC 0.64 8.18 0.06

Hoya Corp 1.67 1.46 0.03

Linde AG Bearer Shs BrShares submitted for exchan 0.10 7.58 0.03

Top 5 Detractors F u n dW e i g h t

AbsoluteReturn*

Portfol ioContr ibut ion

Bayer AG 2.44 -22.10 -0.56

WPP PLC 1.59 -25.00 -0.45

BNP Paribas 1.54 -26.29 -0.43

Credit Suisse Group AG 1.23 -27.45 -0.36

SAP SE 1.53 -19.29 -0.31

Year to Date:

Top 5 Contributors F u n dW e i g h t

AbsoluteReturn*

Portfol ioContr ibut ion

Tata Consultancy ServicesLtd 1.17 37.20 0.39

Hoya Corp 1.57 22.50 0.32

Terumo Corp 1.33 20.75 0.27

Experian PLC 1.32 11.72 0.18

Dassault Systemes SE 0.47 12.00 0.11

Top 5 Detractors F u n dW e i g h t

AbsoluteReturn*

Portfol ioContr ibut ion

Bayer AG 2.53 -42.09 -1.24

WPP PLC 1.89 -37.54 -0.78

Daimler AG 1.80 -34.82 -0.69

BNP Paribas 1.78 -36.27 -0.68

Continental AG 1.00 -47.88 -0.60

RS9093b 418 RS-45350-02

Portfolio Holdings:

Fund Weightings are shown as an average for the time period.*Absolute Return is the return that an asset achieves over a certain period of time. This measure looks at the appreciation or depreciation (expressed as apercentage) that a holding achieves over a given period of time.For a complete listing of fund holdings, visit massmutualfunds.com or please call 1-866-444-2601. The mention of individual stocks and other securities inthis document does not constitute investment advice.

© 2019 Massachusetts Mutual Life Insurance Company (MassMutual), Springfield, MA. All rights reserved. www.massmutual.com Principal Underwriter:MML Distributors, LLC. (MMLD) Member FINRA and SIPC (www.FINRA.org and www.SIPC.org) MMLD is a subsidiary of Massachusetts Mutual LifeInsurance Company, 100 Bright Meadow Blvd., Enfield, CT 06082. Investment advisory services provided to the Funds by MML Investment Advisers, LLC.

MassMutual Select Overseas Fund

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