Fund Russell 1000® Growth Index

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

QTD YTD

Portfolio Attribution: Describes how fund manager sector and stockweighting decisions affected returns.

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

Communication Services 10.81 -0.10 -0.55

Consumer Discretionary 16.28 -0.34 -1.11

Consumer Staples 4.15 -0.14 -0.26

Energy 0.06 -0.00 0.07

Financials 1.85 0.04 -0.05

Health Care 14.71 -0.47 -0.52

Industrials 5.10 -0.07 0.28

Information Technology 44.71 -0.38 -1.40

Materials 0.69 -0.02 -0.04

Real Estate 1.60 0.05 -0.27

Utilities 0.04 -0.01 -0.02

Cash 0.00 -0.01 0.00

Quarterly Portfolio Commentary:

Martin Poirier, CIMA Investment DirectorInvestment Experience: 20 Years

HIGHLIGHTS• The Russell 1000 Growth® Index was the best performing domesticequity index in the quarter.• All but two sectors in the Index delivered positive returns withconsumer discretionary shares delivering the largest gains. • The Fund outperformed its peer group but underperformed itsbenchmark primarily due to unfavorable stock selection. Selection wasweakest in the health care and information technology sectors.• Sector allocation was negative due to modest overweights to thehealth care and financials sectors.

Fund Objective: This Fund seeks to create a diversified portfolio of equity securities in order to outperform the total return performance of itsbenchmark, the Russell 1000® Growth Index*.

The Fund is not promoted, sponsored, or endorsed by, nor in any way affiliated with Russell Investment Group (“Russell”). Russell is not responsible forand has not reviewed the Fund nor any associated literature or publications and Russell makes no representation or warranty, express or implied, as to theiraccuracy, or completeness, or otherwise. The Russell 1000® Growth Index and Russell® are trademarks of the Frank Russell Company.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

I SHARE CLASS TICKER: MPDIX

As of 09/30/2020

MassMutual Premier Disciplined Growth FundBarings LLC

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Quarterly Portfolio Commentary:

Domestic large-cap growth equities were the top performing domestic equity style for the quarter as investors continued to favor companies set tobenefit from secular trends advanced by the COVID-19 pandemic. The leadership of domestic large-cap growth is at or near historical highs, versus large-cap value and small-cap growth and value. Nine of the 11 sectors within the Russell 1000 Growth Index delivered positive returns in the quarter, includingsix sectors delivering double-digit gains. The consumer discretionary sector was the top performing sector in the quarter. Amazon was the largestcontributor in the sector due to its substantial weighting, however Tesla, Carvana, and Peloton Interactive were standouts as each realized share pricegains of more than 70%. Peloton Interactive has seen significant sales growth as consumers avoid traditional gyms in favor of home workout options duringthe pandemic. Despite not being the top performing sector, information technology was the largest contributor to returns due to its substantialrepresentation in the index. The top contributor within the sector was benchmark behemoth Apple, which realized a more than 27% share price gain. Thelone sectors to deliver negative returns in the quarter, utilities and energy, had minimal impact on returns as they comprise less than 10 basis points ofbenchmark weighting.

The Fund outperformed its peer group but underperformed the Russell 1000 Growth Index for the quarter. Stock selection was the primary drag onperformance relative to the benchmark, driven largely by results in three sectors. Returns for stocks in these sectors varied wildly, making them somewhatmore challenging for productive stock selection. Sector allocation was modestly negative.

Stock selection was weakest in the health care, information technolog,y and consumer discretionary sectors. In health care, two pharmaceutical stocksaccounted for the most of the underperformance. An overweight position to AbbVie hurt as the market showed concern about the company’s top-sellingdrug facing increased competition. An overweight to Eli Lilly detracted by nearly the same magnitude. The firm reported disappointing revenue relativeto market expectations. New patient starts for some of the firm’s medicines suffered due to COVID-19 restrictions. In the information technology sector,Fortinet, a firm that develops and markets cybersecurity products, was the top detractor. Their levels of invoicing/ billing disappointed the market in thequarter. A more muted negative impact from sector allocation was driven by the Fund’s overweight to the health care and financials sectors.

There were a number of areas of strength that were beneficial for the quarter. An underweight to the real estate sector was positive as the sectorperformed poorly due to the effects of COVID-19. Stock selection in the financials sector was additive despite the sector being a laggard for the period.PayPal, an online payment firm, provided the greatest absolute contribution. The company reported revenue and earnings expectations that exceededexpectations. The firm has benefited from strong expansion of e-commerce that has been accelerated by the global pandemic.

TICKER: MPDIX Fund Inception: 12/19/2000Morningstar Category: Large Cap Growth

Average Annual Total Return

Q T D Y T D 1 Y 3 Y 5 Y 1 0 Y

MassMutual Premier Disciplined Gr I 11.55% 19.98% 32.63% 18.41% 17.85% 16.12%

Russell 1000® Growth Index 13.22% 24.33% 37.53% 21.67% 20.10% 17.25%

Category Average Returns -- -- 32.13% 18.22% 16.99% 15.01%

Category Rank -- -- 45 50 43 32

# of Funds in Category -- -- 1328 1229 1095 813

Performance shown is for class I shares. Gross expenses = 0.55%, Net expense = 0.55%. Max Sales charge for I is 0.00%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. You cannot invest directly in an index.Pre-Inception Returns - The inception date listed is that of the oldest share class of the Fund. Performance shown subsequent to the inception date

is the actual performance of the share class. Other share classes of the investment itself have existed longer, which accounts for any pre-inceptionperformance shown. The pre-inception performance of Class I for the periods prior to its inception date of (04/01/2014) is based on the performance ofan older share class, Class R5, using the expenses and fees of Class R5 (inception date 11/01/2004). If the expenses of the newer share class was usedrather than the expenses of the old share class (due to lower expenses of the new share class), it would have resulted in better performance.The Fund’s Princ ipa l R isks include - Cash Position Risk, Derivatives Risk, Equity Securities Risk, Frequent Trading/Portfolio Turnover Risk, GrowthCompany Risk, Indexing Risk, Large Company Risk, Liquidity Risk, Management Risk, Market Risk, Quantitative Model Risk, Sector Risk, Valuation Risk.Please refer to the summary prospectus (via the link below or by sending an email to fundinfo@massmutual.com) for more information on the specificrisks.The Morningstar percenti le ranking is based on the fund’s total-return percenti le rank relat ive to 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 (or least favorable) percentile rank is 100%.Morningstar total return includes both income and capital gains or losses and is not adjusted for sales charges. © 2020 Morningstar, Inc. All RightsReserved. The information contained herein: (1) is proprietary to Morningstar and/or its content providers; (2) may not be copied or distributed; and (3) isnot warranted to be accurate, complete or timely. Neither Morningstar nor its content providers are responsible for any damages or losses arising from anyuse of this information.

MassMutual Premier Disciplined Growth Fund

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Quarter to Date:

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

AbsoluteReturn*

Portfol ioContr ibut ion

Apple Inc. 11.79 27.22 2.77

Amazon.com, Inc. 7.67 14.13 1.11

NVIDIA Corporation 1.87 42.50 0.68

Tesla Inc 1.24 98.65 0.65

Facebook, Inc. Class A 4.45 15.34 0.63

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

AbsoluteReturn*

Portfol ioContr ibut ion

AbbVie, Inc. 1.50 -9.72 -0.16

Eli Lilly and Company 1.29 -9.40 -0.15

Vertex PharmaceuticalsIncorporated 0.70 -6.27 -0.05

Regeneron Pharmaceuticals,Inc. 0.51 -10.24 -0.05

Automatic Data Processing,Inc. 0.23 -5.67 -0.03

Year to Date:

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

AbsoluteReturn*

Portfol ioContr ibut ion

Apple Inc. 11.79 58.84 5.07

Amazon.com, Inc. 7.67 70.40 4.58

Microsoft Corporation 9.84 34.43 3.74

NVIDIA Corporation 1.87 130.33 1.57

Facebook, Inc. Class A 4.45 27.60 1.12

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

AbsoluteReturn*

Portfol ioContr ibut ion

Simon Property Group, Inc. 0.33 -54.98 -0.37

Boeing Company 0.00 -39.94 -0.35

Coca-Cola Company 0.58 -8.51 -0.29

Sysco Corporation 0.12 -25.46 -0.21

Merck & Co., Inc. 1.33 -6.66 -0.20

RS9093b RS-48678-03

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.

© 2020 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 Premier Disciplined Growth Fund

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