Fund Holdings As of 06/30/2021 MassMutual Mid Cap Growth Fund T. Rowe Price | Frontier Capital Prior to 5/1/2021, the Fund name was MassMutual Select Mid Cap Growth Fund. Fund Shares or Par Position Market Security Name Ticker CUSIP Weighting (%) Amount Value ($)

Microchip Technology Inc MCHP 595017104 2.07 1,348,381 201,906,571 Agilent Technologies Inc A 00846U101 1.90 1,252,717 185,164,100 Hologic Inc HOLX 436440101 1.84 2,678,942 178,739,010 Teleflex Inc TFX 879369106 1.82 441,297 177,308,722 Ball Corp BLL 058498106 1.75 2,104,895 170,538,593 Textron Inc TXT 883203101 1.55 2,199,000 151,225,230 Burlington Stores Inc BURL 122017106 1.54 465,929 150,024,479 Catalent Inc CTLT 148806102 1.53 1,376,000 148,773,120 Marvell Technology Inc MRVL 573874104 1.46 2,442,368 142,463,325 Bruker Corp BRKR 116794108 1.39 1,776,000 134,940,480 Ingersoll Rand Inc IR 45687V106 1.29 2,564,000 125,148,840 The Cooper Companies Inc COO 216648402 1.28 314,645 124,684,374 KKR & Co Inc Ordinary Shares KKR 48251W104 1.25 2,050,813 121,490,162 Caesars Entertainment Inc CZR 12769G100 1.13 1,057,315 109,696,431 Reserve Invt Fds 0 76105Y208 1.07 103,877,547 103,877,547 DocuSign Inc DOCU 256163106 1.05 366,000 102,322,620 Chipotle Mexican Grill Inc CMG 169656105 1.04 65,283 101,210,846 Dollar General Corp DG 256677105 1.02 460,009 99,541,348 Veeva Systems Inc Class A VEEV 922475108 1.00 314,189 97,697,070 Avantor Inc AVTR 05352A100 0.98 2,700,000 95,877,000 JB Hunt Transport Services Inc JBHT 445658107 0.98 585,000 95,325,750 KLA Corp KLAC 482480100 0.97 291,710 94,575,299 O'Reilly Automotive Inc ORLY 67103H107 0.96 164,452 93,114,367 Keysight Technologies Inc KEYS 49338L103 0.95 598,000 92,337,180 Equifax Inc EFX 294429105 0.94 384,000 91,971,840 Clarivate PLC Ordinary Shares CLVT G21810109 0.93 3,292,000 90,628,760 Hilton Worldwide Holdings Inc HLT 43300A203 0.91 732,000 88,293,840 Mattel Inc MAT 577081102 0.91 4,388,003 88,198,860 TransUnion TRU 89400J107 0.89 791,000 86,859,710 Square Inc A SQ 852234103 0.88 350,117 85,358,525 Fleetcor Technologies Inc FLT 339041105 0.83 317,000 81,171,020 Aptiv PLC APTV G6095L109 0.81 503,000 79,136,990 Fixed Inc Clearing Corp.Repo 0 0 0.80 77,918,966 77,918,966 IDEX Corp IEX 45167R104 0.80 354,000 77,897,700 Rivian Automotive Ser D Cv Tc6wwept2 0 0 0.77 1,076,014 75,385,541 Colfax Corp CFX 194014106 0.77 1,626,000 74,487,060 SVB Financial Group SIVB 78486Q101 0.76 132,482 73,716,959 CoStar Group Inc CSGP 22160N109 0.75 880,000 72,881,600 Casey's General Stores Inc CASY 147528103 0.74 371,000 72,211,440 Inc MTCH 57667L107 0.74 447,000 72,078,750 Cboe Global Markets Inc CBOE 12503M108 0.74 602,000 71,668,100 IAC/InterActiveCorp Ordinary Shares - New IAC 44891N208 0.73 461,684 71,177,822 Ceridian HCM Holding Inc CDAY 15677J108 0.72 731,000 70,117,520 Entegris Inc ENTG 29362U104 0.72 567,000 69,723,990 Incyte Corp INCY 45337C102 0.71 823,817 69,307,724 Corporation PLC A TEAM G06242104 0.71 268,692 69,016,227 Tradeweb Markets Inc TW 892672106 0.70 806,000 68,155,360 Avery Dennison Corp AVY 053611109 0.68 317,000 66,646,080 Inc ROST 778296103 0.68 536,802 66,563,448 Roper Technologies Inc ROP 776696106 0.66 136,000 63,947,200 Inc Ordinary Shares SGEN 81181C104 0.65 398,314 62,885,814 Inc SWKS 83088M102 0.63 321,000 61,551,750 Terminix Global Holdings Inc TMX 88087E100 0.63 1,289,000 61,498,190 Acadia Healthcare Co Inc ACHC 00404A109 0.62 965,000 60,553,750 Fortive Corp FTV 34959J108 0.62 868,000 60,534,320 Sealed Air Corp SEE 81211K100 0.62 1,013,000 60,020,250 Exact Sciences Corp EXAS 30063P105 0.61 478,671 59,503,592 Inc DLTR 256746108 0.61 598,000 59,501,000 Assurant Inc AIZ 04621X108 0.61 380,000 59,348,400 Fund Shares or Par Position Market Security Name Ticker CUSIP Weighting (%) Amount Value ($)

Perrigo Co PLC PRGO G97822103 0.60 1,281,000 58,733,850 Waste Connections Inc WCN 94106B101 0.60 489,737 58,489,290 Etsy Inc ETSY 29786A106 0.60 284,000 58,458,560 Corning Inc GLW 219350105 0.60 1,426,000 58,323,400 Domino's Pizza Inc DPZ 25754A201 0.58 121,820 56,827,812 Fortinet Inc FTNT 34959E109 0.58 238,000 56,689,220 Alcon Inc ALC H01301128 0.58 805,783 56,614,314 Spotify Technology SA SPOT L8681T102 0.58 205,000 56,495,950 Sempra Energy SRE 816851109 0.56 412,000 54,581,760 Black Knight Inc A BKI 09215C105 0.56 697,000 54,352,060 Elanco Animal Health Inc ELAN 28414H103 0.56 1,564,000 54,255,160 Corp CTAS 172908105 0.55 140,462 53,656,484 Inc LULU 550021109 0.53 140,083 51,126,093 Amphenol Corp Class A APH 032095101 0.52 738,066 50,491,095 Paycom Software Inc PAYC 70432V102 0.52 138,858 50,470,717 Bright Horizons Family Solutions Inc BFAM 109194100 0.52 342,481 50,382,380 National Instruments Corp NATI 636518102 0.50 1,150,000 48,622,000 Twilio Inc A TWLO 90138F102 0.50 123,346 48,618,059 Vail Resorts Inc MTN 91879Q109 0.50 153,000 48,427,560 Zynga Inc Class A ZNGA 98986T108 0.48 4,430,000 47,090,900 Roku Inc Class A ROKU 77543R102 0.48 101,428 46,580,809 West Pharmaceutical Services Inc WST 955306105 0.48 129,000 46,323,900 Inc VRSK 92345Y106 0.47 260,000 45,427,200 BWX Technologies Inc BWXT 05605H100 0.47 781,000 45,391,720 Global Payments Inc GPN 37940X102 0.46 240,962 45,190,013 MGM Resorts International MGM 552953101 0.45 1,028,000 43,844,200 Five9 Inc FIVN 338307101 0.45 238,454 43,730,079 Vimeo Inc VMEO 92719V100 0.45 887,644 43,494,556 Corp LRCX 512807108 0.44 65,885 42,871,370 Quidel Corp QDEL 74838J101 0.43 330,000 42,279,600 CrowdStrike Holdings Inc Class A CRWD 22788C105 0.42 164,000 41,214,840 Aon PLC AON G0403H108 0.42 172,477 41,180,609 Alnylam Pharmaceuticals Inc ALNY 02043Q107 0.41 238,000 40,345,760 Live Nation Entertainment Inc LYV 538034109 0.41 459,698 40,264,948 Advance Auto Parts Inc AAP 00751Y106 0.41 195,259 40,055,431 Southwest Airlines Co LUV 844741108 0.41 754,000 40,029,860 MarketAxess Holdings Inc MKTX 57060D108 0.41 86,000 39,868,740 Molina Healthcare Inc MOH 60855R100 0.41 156,583 39,624,894 MSCI Inc MSCI 55354G100 0.39 71,948 38,354,040 Citrix Systems Inc CTXS 177376100 0.39 324,000 37,995,480 Inc MRNA 60770K107 0.37 153,775 36,134,050 Planet Fitness Inc A PLNT 72703H101 0.36 469,693 35,344,398 Liberty Formula One Group C FWONK 531229854 0.36 733,000 35,337,930 argenx SE ADR ARGX 04016X101 0.36 117,000 35,225,190 Inc ALGN 016255101 0.36 57,585 35,184,435 PTC Inc PTC 69370C100 0.36 245,000 34,608,700 Martin Marietta Materials Inc MLM 573284106 0.35 98,000 34,477,380 Axis Capital Holdings Ltd AXS G0692U109 0.34 683,000 33,473,830 Palo Alto Networks Inc PANW 697435105 0.34 89,790 33,316,580 Inc IDXX 45168D104 0.34 52,335 33,052,169 Kirkland Lake Gold Ltd KL 49741E100 0.34 857,000 33,020,210 Alaska Air Group Inc ALK 011659109 0.34 547,000 32,989,570 MongoDB Inc Class A MDB 60937P106 0.34 91,172 32,960,501 RPM International Inc RPM 749685103 0.34 370,000 32,811,600 Leidos Holdings Inc LDOS 525327102 0.33 322,505 32,605,256 Alkermes PLC ALKS G01767105 0.33 1,297,000 31,802,440 Quanta Services Inc PWR 74762E102 0.32 348,949 31,604,311 Boston Beer Co Inc Class A SAM 100557107 0.31 30,000 30,624,000 Floor & Decor Holdings Inc FND 339750101 0.31 287,262 30,363,593 Coupa Software Inc COUP 22266L106 0.31 115,399 30,247,232 ICU Medical Inc ICUI 44930G107 0.31 146,000 30,046,800 Inc SPLK 848637104 0.31 205,914 29,771,046 Broadridge Financial Solutions Inc BR 11133T103 0.31 184,000 29,721,520 Webster Financial Corp WBS 947890109 0.31 557,000 29,710,380 Fund Shares or Par Position Market Security Name Ticker CUSIP Weighting (%) Amount Value ($)

Treehouse Foods Inc THS 89469A104 0.30 654,000 29,116,080 Insulet Corp PODD 45784P101 0.29 104,476 28,679,707 Okta Inc A OKTA 679295105 0.29 117,020 28,632,454 LPL Financial Holdings Inc LPLA 50212V100 0.29 211,416 28,536,932 Ionis Pharmaceuticals Inc IONS 462222100 0.29 707,000 28,202,230 RIVIAN AUTOMOTIVE SERIES D CONVERTIBLE TC6WWEPT 0 0 0.28 393,546 27,571,833 MultiPlan Corp Ordinary Shares - Class A MPLN 62548M100 0.28 2,856,000 27,189,120 Neurocrine Biosciences Inc NBIX 64125C109 0.28 277,000 26,957,640 VF Corp VFC 918204108 0.27 324,000 26,580,960 PPD Inc Ordinary Shares PPD 69355F102 0.27 571,000 26,317,390 MasTec Inc MTZ 576323109 0.27 246,763 26,181,554 Sofi Tech SOFI 83406F102 0.27 1,430,416 26,050,021 Ameren Corp AEE 023608102 0.26 322,000 25,772,880 Packaging Corp of America PKG 695156109 0.26 185,000 25,052,700 Darden Restaurants Inc DRI 237194105 0.25 167,091 24,393,615 DraftKings Inc Ordinary Shares - Class A DKNG 26142R104 0.25 465,000 24,259,050 Farfetch Ltd Class A FTCH 30744W107 0.24 465,000 23,417,400 Inc DXCM 252131107 0.23 53,373 22,790,271 Signify Health Inc Ordinary Shares - Class A SGFY 82671G100 0.23 747,059 22,733,005 Inc AMD 007903107 0.23 241,409 22,675,547 Reynolds Consumer Products Inc Ordinary Shares REYN 76171L106 0.23 738,000 22,398,300 Cree Inc CREE 225447101 0.23 226,499 22,181,047 Pinterest Inc PINS 72352L106 0.23 278,000 21,948,100 Five Below Inc FIVE 33829M101 0.22 109,000 21,066,430 Twitter Inc TWTR 90184L102 0.21 298,252 20,522,720 Dentsply Sirona Inc XRAY 24906P109 0.21 322,000 20,369,720 Bill.com Holdings Inc Ordinary Shares BILL 090043100 0.21 109,000 19,966,620 Steris PLC STE 0 0.20 95,105 19,620,162 Natera Inc NTRA 632307104 0.20 169,857 19,283,865 ORTHO CLINICAL DIAGNOSTICS H COMMON STOCK USD.00001 0 G6829J107 0.20 895,000 19,161,950 Knight-Swift Transportation Holdings Inc A KNX 499049104 0.19 415,053 18,868,309 Cognex Corp CGNX 192422103 0.19 220,000 18,491,000 Genpact Ltd G G3922B107 0.19 402,945 18,305,791 Raymond James Financial Inc RJF 754730109 0.19 139,000 18,056,100 Ultragenyx Pharmaceutical Inc RARE 90400D108 0.18 188,000 17,925,800 Inc ADSK 052769106 0.18 60,283 17,596,608 Leslies Inc Ordinary Shares LESL 527064109 0.18 631,895 17,370,794 Amedisys Inc AMED 023436108 0.17 69,028 16,907,028 NovoCure Ltd NVCR G6674U108 0.17 74,238 16,467,473 Stericycle Inc SRCL 858912108 0.17 228,252 16,331,431 Workday Inc Class A WDAY 98138H101 0.17 68,070 16,251,032 Kemper Corp KMPR 488401100 0.16 217,000 16,036,300 Carvana Co Class A CVNA 146869102 0.16 53,118 16,032,075 Azul SA ADR AZUL 05501U106 0.16 596,461 15,746,570 Moody's Corporation MCO 615369105 0.16 42,964 15,568,865 Jack Henry & Associates Inc JKHY 426281101 0.15 92,000 15,042,920 Illumina Inc ILMN 452327109 0.15 31,405 14,861,160 Eversource Energy ES 30040W108 0.15 184,000 14,764,160 FMC Corp FMC 302491303 0.15 133,410 14,434,962 Guardant Health Inc GH 40131M109 0.15 115,940 14,398,589 BorgWarner Inc BWA 099724106 0.14 289,830 14,068,348 Sherwin-Williams Co SHW 824348106 0.14 49,905 13,596,617 Builders FirstSource Inc BLDR 12008R107 0.14 317,676 13,552,058 KBR Inc KBR 48242W106 0.14 355,084 13,546,455 HubSpot Inc HUBS 443573100 0.14 23,178 13,506,284 Deliveroo Hold Plc Lockup Tc2qbjbd1 0 0 0.14 3,494,800 13,245,171 Shoals Technologies Group Inc Ordinary Shares - Class A SHLS 82489W107 0.13 366,000 12,993,000 Horizon Therapeutics PLC HZNP 0 0.13 138,422 12,961,836 Booz Allen Hamilton Holding Corp Class A BAH 099502106 0.13 151,946 12,942,760 Edwards Lifesciences Corp EW 28176E108 0.13 121,335 12,566,666 Playtika Holding Corp Ordinary Shares PLTK 72815L107 0.13 518,000 12,349,120 DLocal Ltd Class A DLO G29018101 0.12 229,743 12,068,400 Lattice Semiconductor Corp LSCC 518415104 0.12 207,000 11,629,260 Humana Inc HUM 444859102 0.12 26,078 11,545,252 Fund Shares or Par Position Market Security Name Ticker CUSIP Weighting (%) Amount Value ($)

XPO Logistics Inc XPO 983793100 0.12 82,311 11,514,486 Ncino Inc Ordinary Shares NCNO 63947U107 0.11 184,000 11,025,280 Sarepta Therapeutics Inc SRPT 803607100 0.11 141,794 11,023,066 Agilon Health Inc AGL 00857U107 0.11 259,000 10,507,630 Biomarin Pharmaceutical Inc BMRN 09061G101 0.10 114,935 9,590,176 ResMed Inc RMD 761152107 0.10 38,025 9,373,923 Doximity Inc Class A DOCS 26622P107 0.08 140,000 8,148,000 Exelixis Inc EXEL 30161Q104 0.08 438,000 7,980,360 Spac Grsv/Ardagh Pipe Commit Pp Tc6ofvkk5 0 0 0.08 865,381 7,866,313 Sila Nano Ser F Cvt Pfd Pp Tc5s9ax42 0 0 0.08 177,128 7,310,569 Ascendis Pharma A/S ADR ASND 04351P101 0.07 54,000 7,103,700 SelectQuote Inc Ordinary Shares SLQT 816307300 0.06 326,000 6,278,760 Venture Global Lng Inc Sr C Pp Common Stock Pp 0 0 0.06 1,328 6,095,640 Bright Health Group Inc BHG 10920V107 0.06 325,903 5,592,495 GoHealth Inc Ordinary Shares - Class A GOCO 38046W105 0.06 494,000 5,537,740 Kodiak Sciences Inc KOD 50015M109 0.05 57,000 5,301,000 SentinelOne Inc Class A S 81730H109 0.05 121,114 5,147,345 Caris Life Ser D Cvt Pfd Tc13pnhl5 0 0 0.05 618,025 5,006,002 Procore Tech Lock Up Shrs Tc9wxfxr0 0 0 0.05 54,836 4,946,344 Array Technologies Inc Ordinary Shares ARRY 04271T100 0.05 283,833 4,427,795 Confluent Inc Class A CFLT 20717M103 0.04 89,000 4,227,500 Clear Secure Inc Ordinary Shares Class A YOU 18467V109 0.04 97,028 3,881,120 Redwood Materials Ser C Tc25hizf2 0 0 0.04 77,608 3,678,888 Procore Technologies Inc PCOR 74275K108 0.03 30,079 2,856,001 Databricks Ser G Cvt Pfd Pp Tc6xlxuh0 0 0 0.02 13,535 2,400,703 Dragoneer Growth Opportunities Corp Ordinary Shares - Class A DGNR G28302100 0.02 238,000 2,370,480 Spac Dgnr Ccc Sys Pipe Pp Tc8pn0yw8 0 0 0.02 241,702 2,166,617 LegalZoom.com Inc LZ 52466B103 0.02 48,002 1,816,876 Maplebear Dba Instacart Ser I Tc3g4c2x1 0 0 0.02 14,123 1,765,375 Squarespace Inc Class A SQSP 85225A107 0.02 24,576 1,460,060 Venture Global Lng Inc Sr B P Common Stock (Priv Plcmt.) 0 0 0.01 216 991,459 Jand (Dba Wp) Ser Aa Cvt Pp Tc35yfez7 0 0 0.01 30,753 754,390 Wework Companies Inc Series D1 Preferred 0 0 0.01 83,736 716,734 Pershing Square Tontine Hldg ([Wts/Rts]) 0% 0 71531R117 0.01 80,019 504,120 Jand Inc. Class A Common Sh Common Stock 0 0 0.00 14,855 364,402 Wework Companies Inc Series D2 Preferred 0 0 0.00 36,452 312,009 Jand (Dba Wp) Ser B Cvt Pp Tc3387om7 0 0 0.00 41 1,006

Investors should carefully consider investment objectives, risks, charges and expenses. This and other important information is contained in the fund prospectuses and summary prospectuses, which can be obtained from www.MassMutual.com/mmfunds/ and should be read carefully before investing.

The mention of individual stocks and other securities in this document does not constitute investment advice.

© 2021 Massachusetts Mutual Life Insurance Company (MassMutual®), Springfield, MA. All rights reserved. www.MassMutual.com Principal Underwriter: MML Distributors, LLC. (MMLD), 1295 State St., Springfield, MA 01111. Member FINRA and SIPC (www.FINRA.org and www.SIPC.org). Investment advisory services provided to the Funds by MML Investment Advisers, LLC (MML Investment Advisers). MMLD and MML Investment Advisers are subsidiaries of Massachusetts Mutual Life Insurance Company (MassMutual), Springfield, MA 01111-0001.

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