<Page>
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM N-CSR
CERTIFIED SHAREHOLDER REPORT OF REGISTERED
MANAGEMENT INVESTMENT COMPANIES
Investment Company Act file number 811-02224
---------------------------------------------
MML Series Investment Fund
- --------------------------------------------------------------------------------
(Exact name of registrant as specified in charter)
1295 State Street, Springfield, MA 01111
- --------------------------------------------------------------------------------
(Address of principal executive offices) (Zip code)
David W. O'Leary
1295 State Street, Springfield, MA 01111
- --------------------------------------------------------------------------------
(Name and address of agent for service)
Registrant's telephone number, including area code: 413-788-8411
----------------
Date of fiscal year end: 12/31/2004
------------
Date of reporting period: 12/31/2004
-----------
<Page>
ITEM 1 REPORTS TO STOCKHOLDERS.
<Page>
MML SERIES INVESTMENT FUND
ANNUAL REPORT
FOR THE YEAR ENDED
DECEMBER 31, 2004
[GRAPHIC]
MML EQUITY INDEX FUND
MML SMALL CAP EQUITY FUND
INVEST
INSURE
RETIRE
[MASSMUTUAL FINANCIAL GROUP(SM) LOGO]
YOU CAN'T PREDICT. YOU CAN PREPARE(R).
<Page>
TABLE OF CONTENTS
<Table>
PORTFOLIO MANAGER REPORTS 1
PORTFOLIO OF INVESTMENTS 7
MML Equity Index Fund 7
MML Small Cap Equity Fund 13
STATEMENT OF ASSETS AND LIABILITIES 15
STATEMENT OF OPERATIONS 16
STATEMENT OF CHANGES IN NET ASSETS 17
FINANCIAL HIGHLIGHTS 18
NOTES TO FINANCIAL STATEMENTS 21
INDEPENDENT AUDITORS' REPORT 29
DIRECTORS AND OFFICERS (UNAUDITED) 30
FEDERAL TAX INFORMATION (UNAUDITED) 32
FUND EXPENSES (UNAUDITED) 33
</Table>
THIS MATERIAL MUST BE PRECEDED OR ACCOMPANIED BY A CURRENT PROSPECTUS FOR THE
MML SERIES INVESTMENT FUND. INVESTORS SHOULD CONSIDER A FUND'S INVESTMENT
OBJECTIVE, RISKS AND CHARGES AND EXPENSES CAREFULLY BEFORE INVESTING. THIS AND
OTHER INFORMATION ABOUT THE INVESTMENT COMPANY IS AVAILABLE IN THE PROSPECTUS.
READ IT CAREFULLY BEFORE INVESTING.
<Page>
MML SERIES INVESTMENT FUND - LETTER TO SHAREHOLDERS
[PHOTO OF DAVID O'LEARY]
DAVID O'LEARY
"IN MASSMUTUAL'S VIEW, INVESTORS SHOULD FOCUS ON THE LONG TERM, WITH A PORTFOLIO
THAT IS APPROPRIATELY DIVERSIFIED BASED ON THEIR FINANCIAL GOALS, TIME HORIZON
AND RISK COMFORT LEVEL. STAYING THE COURSE WITH TIME-TESTED PRINCIPLES, SUCH AS
DIVERSIFICATION, HAS HISTORICALLY PROVEN TO BE A SOUND STRATEGY."
A LOOK BACK AT 2004
During the first half of 2004, the strong market advance of 2003 lost much of
its momentum, as unsettling geopolitical developments, a nebulous market
environment and the uncertainty surrounding the U.S. presidential election
weighed on investors' minds. Although the larger-cap and technology-oriented
market indexes lost some traction in the first quarter, the S&P 500 Index(R)*
held its ground and small-cap and international stocks advanced. The bond market
also benefited from slightly lower interest rates.
A seesaw of positives and negatives kept many investors from making definitive
moves in the second quarter. Despite stronger economic growth and corporate
profits, greater consumer confidence and improving employment statistics, higher
oil prices, renewed inflation concerns and continued terrorist threats unnerved
investors. As a result, many market indexes turned in nearly flat returns.
In the third quarter, stocks lost ground as high energy prices, rising interest
rates, presidential election jitters and the worst hurricane season in 40 years
kept investors on the defensive. Bonds outperformed stocks, despite two
increases in short-term interest rates by the Federal Reserve (Fed).
As 2004 drew to a close, many investors saw gains in the major stock indexes for
both the fourth quarter and the year itself. The fixed income rally that had
buoyed bond prices for a good portion of the year slowed considerably in the
middle of the fourth quarter. Underscoring investor preference for technology
stocks over blue chips as 2004 wound down, the Nasdaq Composite Index and Dow
Jones Industrial Average returned 14.69% and 7.48% for the quarter and 8.59% and
5.29% for the year, respectively. Small-cap stocks easily outdistanced large
caps on both a quarterly basis and for the year. International stocks benefited
from the continued weakening of the dollar relative to other currencies, as the
MSCI EAFE Index outperformed nearly every other major equity index. Despite an
investment trend away from fixed income and toward equities, many bond investors
still notched positive returns for the year.
As with much of the year, economic news in the fourth quarter was generally
mixed. Many investors were encouraged by a swift resolution to the presidential
election and reports of an overall improvement in economic fundamentals.
However, gyrating oil prices, predictions about a weak holiday retailing season,
weak statistics for new home sales and mortgage applications and concerns about
corporate earnings kept an equity rally from sustaining momentum until the
second half of the fourth quarter, when a series of economic reports pointed to
solid expansion and an improved outlook.
THE ROLE OF THE WEAKENING DOLLAR
In the fourth quarter of 2004, the U.S. dollar declined dramatically relative to
its key benchmark currencies, including the euro, the Japanese yen and the
British pound. The strong performance of international markets in 2004 directly
correlates to the dollar's weakness. Currency rates suddenly became a focus for
investors, who wondered about the impact to their portfolios and whether a
falling dollar could be both negative and positive. The answer seems to be yes -
depending on your perspective.
- ----------
* Indexes are unmanaged, do not incur fees or expenses and cannot be purchased
directly for investment.
i
<Page>
Put simply, a dollar that is strengthening can buy more units of a foreign
currency; a weakening dollar will buy fewer. When the dollar strengthens, the
prices of goods and services produced abroad go down for American consumers, who
have more purchasing power to buy foreign securities, and a better rate of
exchange when traveling abroad. Viewed differently, a strong dollar means that
U.S. companies have greater difficulty doing business internationally, as they
must compete with the lower prices of foreign products. Conversely, when the
value of the dollar declines, foreign products become more expensive for U.S.
buyers, U.S. companies can offer more competitive pricing on products overseas,
foreign travelers find the U.S. to be more affordable, and securities
denominated in dollars become more attractive. On the other hand, the prices of
foreign-produced goods become higher for U.S. buyers - whose travel to other
countries may become cost-prohibitive and whose foreign securities purchasing
power diminishes.
OUTLOOK
The weakening dollar notwithstanding, as we look toward 2005, there are various
encouraging economic signs on the horizon. Inflation and interest rates are
still low and economic expansion has been widely substantiated. Reports on
personal income, consumer confidence and durable goods have suggested the
economy may sustain above-average growth in the near term, all of which could
translate into stronger corporate earnings figures and higher stock prices. The
Fed will likely continue to raise interest rates at a measured pace - in tandem
with a potentially stronger equity environment, this may present a challenge to
bond investors.
In summary, MassMutual continues to believe that investors should focus on the
long term, with a portfolio that is appropriately diversified based on their
financial goals, time horizon and risk comfort level. Staying the course with
time-tested principles, such as diversification, has historically helped
investors reach their goals, although past performance is no guarantee of future
results.
/s/ David W. O'Leary
David W. O'Leary
PRESIDENT
THE OPINIONS EXPRESSED HEREIN ARE THOSE OF MASSMUTUAL AS OF JANUARY 1, 2005 AND
ARE SUBJECT TO CHANGE WITHOUT NOTICE. THIS INFORMATION IS NOT TO BE CONSTRUED AS
TAX, LEGAL OR INVESTMENT ADVICE.
ii
<Page>
MML EQUITY INDEX FUND - PORTFOLIO MANAGER REPORT
WHAT IS THE INVESTMENT OBJECTIVE OF THE MML EQUITY INDEX FUND?
The Fund seeks to approximate as closely as practicable (before fees and
expenses) the capitalization-weighted total rate of return of that portion of
the U.S. market for publicly traded common stocks composed of larger-capitalized
companies. The Fund pursues this objective by investing at least 80% of its
assets in the equity securities of companies that make up the S&P 500 Index(R).
HOW DID THE FUND PERFORM DURING 2004?
For the 12 months ended December 31, 2004, the Fund's Class I shares returned
10.42%, nearly in line with the 10.88% return of the S&P 500 Index(R), a
market-capitalization-weighted, unmanaged index of 500 common stocks.
WHAT WAS THE INVESTMENT BACKDROP DURING THE PERIOD?
While the U.S. economy continued to demonstrate signs of improvement during the
first few months of 2004, a muted improvement in job growth dampened enthusiasm.
Given the pace of economic growth, the sluggish job market implied a significant
increase in corporate productivity, expected to translate into continued strong
corporate profits. In this environment, value stocks continued to outpace growth
stocks as they did in 2003.
During the second quarter, the U.S. economy was positively impacted by a number
of factors, including a rise in consumer confidence, rising corporate profits
and improvements in the labor market, although the market was held back by a
number of factors, including concerns of a Federal Reserve (Fed) interest rate
hike and the handover of power in Iraq. The market gained some stability with
both events taking place uneventfully at the end of June; however, investors
remained cautious. Fixed-income markets struggled during the period, sparked by
the rate increase and anticipation of further increases.
In the third quarter, rapidly increasing oil prices, continued global
instability and concerns over the lack of job growth tempered the performance of
U.S. equity markets. The Fed raised the federal funds rate by 0.25% and affirmed
its expectations that the flow of future economic data would support continued
tightening at a measured pace. Bonds outperformed stocks for the quarter by
approximately five percentage points. Global equity markets generally fared
better than the U.S. equity markets, led by favorable performance across Europe.
The U.S. economy rallied again in the fourth quarter. Economic growth, changing
from a consumption-driven trend to one fueled by business and business
investment, advanced slightly, although corporate executives were cautiously
optimistic. Inflation remained relatively under control, and expectations
continued that the Fed would maintain a measured pace of interest rate
increases. Although the dollar, on a trade-weighted basis, continued to decline,
the desirability of U.S. assets remained quite high.
WHAT FACTORS CONTRIBUTED TO THE FUND'S PERFORMANCE?
In the first quarter, sector performance was mixed. The financials sector
provided the greatest contribution to the market's return; consumer staples and
energy also helped boost Index performance. Conversely, the information
technology sector, which drove the performance of the Index in 2003, lagged in
the first quarter.
Sector results were also mixed in the second quarter, as the financial services
sector, which has the largest weight in the S&P 500, underperformed all other
groups. On the other hand, the S&P's second-largest sector, information
technology, advanced for the period. Energy was the best-performing sector.
Continuing the trend of the prior two quarters, sector performance throughout
the third quarter was mixed. The energy sector, driven by the rise in oil
prices, advanced the most, while information technology turned in the worst
performance, losing ground during the period.
During the final quarter of 2004, all sectors generated results of 4.7% or
better, with the information technology sector's double-digit advance leading
the way. The financials sector also drove performance for the period.
1
<Page>
MML EQUITY INDEX FUND
INDUSTRY TABLE
(% OF NET ASSETS) ON 12/31/04
<Table>
Banking, Savings & Loans 11.8%
Pharmaceuticals 8.5%
Energy 7.2%
Electrical Equipment & Electronics 6.8%
Retail 5.7%
Insurance 5.0%
Computers & Information 4.4%
Prepackaged Software 4.2%
Financial Services 3.9%
Broadcasting, Publishing & Printing 2.8%
Electric Utilities 2.7%
Medical Supplies 2.4%
Cosmetics & Personal Care 2.3%
Beverages 2.2%
Communications 2.2%
Telephone Utilities 2.2%
Commercial Services 2.0%
Foods 1.9%
Aerospace & Defense 1.9%
Transportation 1.9%
Industrial - Diversified 1.9%
Chemicals 1.6%
Tobacco 1.3%
Healthcare 1.1%
Entertainment & Leisure 1.0%
Automotive & Parts 1.0%
Machinery & Components 0.9%
Computers & Office Equipment 0.9%
Data Processing & Preparation 0.8%
Apparel, Textiles & Shoes 0.8%
Metals & Mining 0.7%
Household Products 0.6%
Restaurants 0.6%
Forest Products & Paper 0.5%
Information Retrieval Services 0.4%
Manufacturing 0.4%
Computer Integrated Systems Design 0.4%
Communications Equipment 0.4%
Lodging 0.3%
Home Construction, Furnishings & Appliances 0.3%
Advertising 0.2%
Building Materials & Construction 0.2%
Real Estate 0.2%
Containers 0.2%
Air Transportation 0.1%
Toys, Games 0.1%
Photography Equipment/ Supplies 0.1%
Retail - Grocery 0.1%
Industrial - Distribution 0.1%
Computer Programming Services 0.0%
Travel 0.0%
Futures 0.0%
Short-Term Investments and Other Assets and Liabilities 0.8%
-----
100.0%
=====
</Table>
MML EQUITY INDEX FUND
LARGEST STOCK HOLDINGS (12/31/04)
General Electric Co.
Exxon Mobil Corp.
Microsoft Corp.
Citigroup, Inc.
Wal-Mart Stores, Inc.
Pfizer, Inc.
Bank of America Corp.
Johnson & Johnson
American International Group, Inc.
International Business Machines Corp.
2
<Page>
GROWTH OF A $10,000 INVESTMENT
Hypothetical Investments in MML Equity Index Fund Class I and the S&P 500 Index.
MML SERIES INVESTMENT FUND
TOTAL RETURN
<Table>
<Caption>
FIVE YEAR SINCE INCEPTION
ONE YEAR AVERAGE ANNUAL AVERAGE ANNUAL
1/1/04 - 12/31/04 1/1/00 - 12/31/04 5/1/97 - 12/31/04
ML Equity Index
Fund Class I 10.42% -2.75% 6.63%
S&P 500 Index 10.88% -2.30% 7.15%
</Table>
Hypothetical Investments in MML Equity Index Fund Class II, Class III and the
S&P 500 Index
MML SERIES INVESTMENT FUND
TOTAL RETURN
<Table>
<Caption>
SINCE INCEPTION
ONE YEAR AVERAGE ANNUAL
1/1/04 - 12/31/04 5/1/00 - 12/31/04
MML Equity Index Fund Class II 10.60% -2.58%
MML Equity Index Fund Class III 10.77% -2.51%
S&P 500 Index 10.88% -2.29%
</Table>
[CHART]
GROWTH OF A $10,000 INVESTMENT SINCE INCEPTION
<Table>
<Caption>
CLASS I S&P 500 Index
5/1/97 $ 10,000 $ 10,000
12/97 $ 12,193 $ 12,255
12/98 $ 15,634 $ 15,757
12/99 $ 18,811 $ 19,073
12/00 $ 17,018 $ 17,338
12/01 $ 14,921 $ 15,279
12/02 $ 11,569 $ 11,903
12/03 $ 14,818 $ 15,316
12/04 $ 16,362 $ 16,981
</Table>
[CHART]
<Table>
<Caption>
CLASS II CLASS III S&P 500 INDEX
5/1/2000 $ 10,000 $ 10,000 $ 10,000
12/00 $ 9,137 $ 9,150 $ 9,162
12/01 $ 8,024 $ 8,024 $ 8,074
12/02 $ 6,236 $ 6,244 $ 6,290
12/03 $ 8,001 $ 8,016 $ 8,094
12/04 $ 8,849 $ 8,879 $ 8,974
</Table>
PERFORMANCE DATA QUOTED REPRESENTS PAST PERFORMANCE; PAST PERFORMANCE IS NOT
PREDICTIVE OF FUTURE RESULTS. THE INVESTMENT RETURN AND PRINCIPAL VALUE OF
SHARES OF THE FUND WILL FLUCTUATE WITH MARKET CONDITIONS SO THAT SHARES OF THE
FUND, WHEN REDEEMED, MAY BE WORTH MORE OR LESS THAN THEIR ORIGINAL COST. CURRENT
PERFORMANCE OF THE FUND MAY BE LOWER OR HIGHER THAN THE PERFORMANCE QUOTED.
PERFORMANCE DATA CURRENT TO THE MOST RECENT MONTH END MAY BE OBTAINED BY
ACCESSING THE WEBSITE AT www.massmutual.com.
INVESTORS SHOULD NOTE THAT THE FUND IS A PROFESSIONALLY MANAGED MUTUAL FUND,
WHILE THE S&P 500 INDEX IS UNMANAGED AND DOES NOT INCUR EXPENSES, AND CANNOT BE
PURCHASED DIRECTLY BY INVESTORS. INVESTORS SHOULD READ THE FUND'S PROSPECTUS
WITH REGARD TO THE FUND'S INVESTMENT OBJECTIVE, RISKS AND CHARGES AND EXPENSES
IN CONJUNCTION WITH THESE FINANCIAL STATEMENTS. THE FUND'S RETURN REFLECTS
CHANGES IN THE NET ASSET VALUE PER SHARE WITHOUT THE DEDUCTION OF ANY PRODUCT
CHARGES. TOTAL RETURN FIGURES WOULD BE LOWER FOR THE PERIODS PRESENTED IF THEY
REFLECTED THESE CHARGES.
3
<Page>
MML SMALL CAP EQUITY FUND - PORTFOLIO MANAGER REPORT
WHAT IS THE INVESTMENT OBJECTIVE OF THE MML SMALL CAP EQUITY FUND?
This Fund seeks to achieve long-term growth of capital and income by investing
primarily in a diversified portfolio of equity securities of smaller companies.
HOW DID THE FUND PERFORM DURING 2004?
For the 12 months ended December 31, 2004, the Fund's shares returned 16.36%,
trailing the 18.33% return of the Russell 2000 Index, a broadly based, unmanaged
index of 2000 small-capitalization common stocks.
WHAT WAS THE INVESTMENT BACKGROUND DURING THE PERIOD?
Equity markets recorded modest gains in the first quarter of 2004, as renewed
concerns over terrorism and rising oil prices dampened investor psychology and
enthusiasm after a strong start in January. Job growth improved during the
period; other positive indicators included favorable corporate earnings,
declining interest rates and healthy consumer spending.
During the second quarter, equities posted only a slight gain, as a bit of a
holding pattern set in due to anxiety over how much and when the Federal Reserve
would raise interest rates. Investors got closure at the end of June, when the
central bank boosted rates for the first time since May 2000 by a quarter of a
percentage point. Equity markets, relieved, rose modestly. Additional economic
measures released during the quarter were largely favorable, although a few
wrinkles remained - namely jobs and oil.
Third quarter equity market performance resembled a roller-coaster ride. Early
in the quarter, factors such as higher interest rates, rising oil prices and
weak economic data drove markets lower. Things turned around in the middle of
August, when longer-term interest rates trended lower and bargain hunters
feasted on attractive equity valuations. In September, however, headwinds -
including record oil prices and presidential election uncertainty - cast a chill
on the markets.
Equity markets closed 2004 on a strong note, finishing a second straight year in
positive territory. With a major element of uncertainty - political leadership -
eliminated, investors refocused on major economic indicators, such as
strengthening job creation and improved consumer confidence.
WHAT FACTORS CONTRIBUTED TO THE FUND'S PERFORMANCE?
During the first quarter of 2004, less-than-favorable stock selection hindered
the Fund's progress. In particular, our choices in the consumer discretionary,
financial services and health care sectors hampered performance. The Fund's
emphasis on oil services companies in the energy sector and semiconductor names
in the technology sector also detracted from results, as both areas experienced
a significant price correction during the quarter. Conversely, the Fund
experienced strong results in autos/transportation.
In the second quarter, favorable stock selection, from the autos/transportation
and financial services sectors to the producer durables and technology sectors,
helped to drive returns. Several of the Fund's energy services holdings and
companies specializing in electrical components and equipment realized
particularly strong results. Additionally, in technology, the Fund's holdings
significantly outperformed corresponding benchmark positions and in the consumer
discretionary sector, our holdings added value. The Fund's health care stocks
hampered performance somewhat, although the portfolio held only minimal
positions.
Performance for the Fund's technology holdings was weak in the third quarter,
particularly for a few holdings in the semiconductor space. Our stock selection
was also weak in the financial services and health care sectors. With respect to
areas of strength, our results continued to be highly favorable in the other
energy and autos and transportation sectors, where several energy services
holdings and companies specializing in shipping realized particularly strong
results.
In the final quarter of 2004, our stock selection turned out to be largely
favorable across most economic sectors, with particular strength in the
financial services, materials and processing, and health care sectors. The
portfolio's holdings in the autos and transportation sector, a leading area in
2004, also performed strongly. Areas of weakness relative to the Russell 2000
Index were the technology, producer durables and consumer discretionary sectors.
4
<Page>
WHAT IS YOUR OUTLOOK?
Our 2005 outlook for the U.S. stock market assumes that profit growth will
decelerate from 2004 levels and settle in the 8% to 10% range. It is likely the
market could face downward pressure on valuations as interest rates rise. If
these two trends materialize, we may be faced with a lackluster year for
equities. Conversely, the stock market should be able to take in stride rising
interest rates, as long as the increases are gradual and inflation does not
become troublesome.
MML SMALL CAP EQUITY FUND
INDUSTRY TABLE
(% OF NET ASSETS) ON 12/31/04
<Table>
Machinery & Components 13.1%
Financial Services 10.5%
Banking, Savings & Loans 9.2%
Electrical Equipment & Electronics 8.9%
Transportation 6.7%
Energy 6.7%
Insurance 6.0%
Commercial Services 6.0%
Medical Supplies 4.5%
Broadcasting, Publishing & Printing 2.9%
Pharmaceuticals 2.9%
Chemicals 2.8%
Retail 2.5%
Industrial - Diversified 1.9%
Home Construction, Furnishings & Appliances 1.8%
Household Products 1.7%
Apparel, Textiles & Shoes 1.5%
Prepackaged Software 1.4%
Restaurants 1.3%
Air Transportation 1.1%
Computer Related Services 0.9%
Cosmetics & Personal Care 0.6%
Telephone Utilities 0.2%
Metals & Mining 0.2%
Short-Term Investments and Other Assets and Liabilities 4.7%
-----
100.0%
=====
</Table>
MML SMALL CAP EQUITY FUND
LARGEST STOCK HOLDINGS (12/31/04)
Eaton Vance Corp.
Roper Industries, Inc.
The Commerce Group, Inc.
Landstar System, Inc.
Jefferies Group, Inc.
Heartland Express, Inc.
Coldwater Creek, Inc.
Kaydon Corp.
Teleflex, Inc.
First Republic Bank
5
<Page>
GROWTH OF A $10,000 INVESTMENT
Hypothetical Investments in MML Small Cap Equity Fund and the Russell 2000 Index
MML SERIES INVESTMENT FUND
<Table>
<Caption>
TOTAL RETURN FIVE YEAR SINCE INCEPTION
ONE YEAR AVERAGE ANNUAL AVERAGE ANNUAL
1/1/04 - 12/31/04 1/1/00 - 12/31/04 6/1/98 - 12/31/04
MML Small Cap
Equity Fund 16.36% 9.60% 4.47%
Russell 2000 Index 18.33% 6.61% 6.93%
</Table>
[CHART]
GROWTH OF A $10,000 INVESTMENT SINCE INCEPTION
<Table>
<Caption>
MML SMALL CAP EQUITY FUND RUSSELL 2000 INDEX
6/1/98 $ 10,000 $ 10,000
12/98 $ 8,522 $ 9,307
12/99 $ 8,433 $ 11,286
12/00 $ 9,583 $ 10,945
12/01 $ 9,904 $ 11,217
12/02 $ 8,732 $ 8,919
12/03 $ 11,464 $ 13,134
12/04 $ 13,339 $ 15,541
</Table>
PERFORMANCE DATA QUOTED REPRESENTS PAST PERFORMANCE; PAST PERFORMANCE IS NOT
PREDICTIVE OF FUTURE RESULTS. THE INVESTMENT RETURN AND PRINCIPAL VALUE OF
SHARES OF THE FUND WILL FLUCTUATE WITH MARKET CONDITIONS SO THAT SHARES OF THE
FUND, WHEN REDEEMED, MAY BE WORTH MORE OR LESS THAN THEIR ORIGINAL COST. CURRENT
PERFORMANCE OF THE FUND MAY BE LOWER OR HIGHER THAN THE PERFORMANCE QUOTED.
PERFORMANCE DATA CURRENT TO THE MOST RECENT MONTH END MAY BE OBTAINED BY
ACCESSING THE WEBSITE AT www.massmutual.com.
INVESTORS SHOULD NOTE THAT THE FUND IS A PROFESSIONALLY MANAGED MUTUAL FUND,
WHILE THE RUSSELL 2000 INDEX IS UNMANAGED AND DOES NOT INCUR EXPENSES, AND
CANNOT BE PURCHASED DIRECTLY BY INVESTORS. INVESTORS SHOULD READ THE FUND'S
PROSPECTUS WITH REGARD TO THE FUND'S INVESTMENT OBJECTIVE, RISKS AND CHARGES AND
EXPENSES IN CONJUNCTION WITH THESE FINANCIAL STATEMENTS. THE FUND'S RETURN
REFLECTS CHANGES IN THE NET ASSET VALUE PER SHARE WITHOUT THE DEDUCTION OF ANY
PRODUCT CHARGES. TOTAL RETURN FIGURES WOULD BE LOWER FOR THE PERIODS PRESENTED
IF THEY REFLECTED THESE CHARGES.
6
<Page>
MML EQUITY INDEX FUND - PORTFOLIO OF INVESTMENTS
DECEMBER 31, 2004
<Table>
<Caption>
NUMBER OF MARKET
SHARES VALUE
----------- -------------
EQUITIES -- 99.2%
ADVERTISING -- 0.2%
Interpublic Group of
Companies, Inc.* + 14,807 $ 198,414
Monster Worldwide, Inc.* 4,276 143,845
Omnicom Group, Inc. 6,706 565,450
-------------
907,709
-------------
AEROSPACE & DEFENSE -- 1.9%
Boeing Co. 29,969 1,551,495
General Dynamics Corp. 7,107 743,392
Goodrich Corp. 4,239 138,361
Honeywell
International, Inc. 30,690 1,086,733
Lockheed Martin Corp. 15,940 885,467
Northrop Grumman Corp. 12,868 699,504
Raytheon Co. 16,088 624,697
Rockwell Collins, Inc. 6,368 251,154
United Technologies Corp. 18,311 1,892,442
-------------
7,873,245
-------------
AIR TRANSPORTATION -- 0.1%
Delta Air Lines, Inc.* + 4,499 33,653
Southwest Airlines Co. 28,240 459,747
-------------
493,400
-------------
APPAREL, TEXTILES & SHOES -- 0.8%
Coach, Inc.* 6,700 377,880
The Gap, Inc. 31,245 659,894
Jones Apparel Group, Inc. 4,496 164,419
Limited Brands 14,430 332,179
Liz Claiborne, Inc. 3,874 163,522
Nike, Inc. Cl. B 9,424 854,663
Nordstrom, Inc. 5,035 235,286
Reebok International
Limited+ 2,156 94,864
VF Corp. 3,951 218,806
-------------
3,101,513
-------------
AUTOMOTIVE & PARTS -- 1.0%
AutoNation, Inc.* 9,600 184,416
Cooper Tire &
Rubber Co.+ 2,346 50,556
Dana Corp. 5,303 91,901
Delphi Corp.+ 20,083 181,149
Ford Motor Co.+ 65,367 956,973
General Motors Corp.+ 20,130 806,408
Genuine Parts Co. 6,229 274,450
The Goodyear Tire &
Rubber Co.* + 6,265 91,845
Harley-Davidson, Inc. 10,520 639,090
Navistar
International Corp.* 2,474 $ 108,807
Paccar, Inc.+ 6,183 497,608
Visteon Corp.+ 4,612 45,059
-------------
3,928,262
-------------
BANKING, SAVINGS & LOANS -- 11.8%
AmSouth Bancorporation+ 12,659 327,868
Bank of America Corp. 143,992 6,766,184
Bank of New York Co., Inc. 27,845 930,580
BB&T Corp. 19,783 831,875
Capital One Financial Corp. 8,600 724,206
Citigroup, Inc. 185,044 8,915,420
Comerica, Inc.+ 6,169 376,432
Compass Bancshares, Inc. 3,800 184,946
Fannie Mae 34,576 2,462,157
Fifth Third Bancorp+ 20,363 962,763
First Horizon
National Corp.+ 4,400 189,684
Freddie Mac 24,586 1,811,988
Golden West
Financial Corp. 10,910 670,092
JP Morgan Chase & Co. 127,247 4,963,905
KeyCorp+ 14,510 491,889
M&T Bank Corp. 4,200 452,928
Marshall and Ilsley Corp. 8,000 353,600
Mellon Financial Corp. 15,194 472,685
National City Corp.+ 23,698 889,860
North Fork
Bancorporation, Inc. 16,750 483,237
Northern Trust Corp. 8,488 412,347
Providian
Financial Corp.* + 10,502 172,968
Regions Financial Corp. 16,470 586,167
SLM Corp. 15,542 829,787
Sovereign Bancorp, Inc.+ 11,677 263,316
State Street Corp. 12,022 590,521
SunTrust Banks, Inc. 12,790 944,925
Synovus Financial Corp. 11,063 316,181
U.S. Bancorp 67,132 2,102,574
Wachovia Corp. 57,351 3,016,663
Washington Mutual, Inc. 31,376 1,326,577
Wells Fargo & Co. 60,329 3,749,447
Zions Bancorp 3,193 217,220
-------------
47,790,992
-------------
BEVERAGES -- 2.2%
Anheuser-Busch
Companies, Inc. 28,148 1,427,948
Brown-Forman Corp. Cl. B 4,380 213,218
The Coca-Cola Co. 86,676 3,608,322
Coca-Cola
Enterprises, Inc. 16,774 $ 349,738
Coors (Adolph) Co. Cl. B+ 1,289 97,539
The Pepsi Bottling
Group, Inc.+ 9,038 244,388
PepsiCo, Inc. 60,008 3,132,418
-------------
9,073,571
-------------
BROADCASTING, PUBLISHING & PRINTING -- 2.8%
Clear Channel
Communications, Inc. 20,449 684,837
Comcast Corp. Cl. A* 79,118 2,633,047
Dow Jones & Co., Inc.+ 2,926 125,994
Gannett Co., Inc. 9,135 746,329
Knight Ridder, Inc.+ 2,755 184,420
The McGraw-Hill
Companies, Inc. 6,830 625,218
Meredith Corp. 1,844 99,945
New York Times Co. Cl. A+ 5,265 214,812
Time Warner, Inc.* 163,408 3,176,652
Tribune Co. 11,409 480,775
Univision Communications,
Inc. Cl. A* + 11,600 339,532
Viacom, Inc. Cl. B 60,768 2,211,348
-------------
11,522,909
-------------
BUILDING MATERIALS & CONSTRUCTION -- 0.2%
Louisiana-Pacific Corp. 3,856 103,109
Masco Corp. 15,467 565,010
Vulcan Materials Co. 3,610 197,142
-------------
865,261
-------------
CHEMICALS -- 1.6%
Air Products &
Chemicals, Inc. 8,158 472,919
Ashland, Inc. 2,503 146,125
Dow Chemical Co. 33,568 1,661,952
Du Pont (E.I.) de
Nemours & Co. 35,604 1,746,376
Eastman Chemical Co. 2,800 161,644
Engelhard Corp. 4,393 134,733
Great Lakes
Chemical Corp.+ 1,855 52,849
Hercules, Inc.* 4,006 59,489
International Flavors &
Fragrances, Inc. 3,346 143,343
Monsanto Co. 9,585 532,447
PPG Industries, Inc. 6,089 415,026
Praxair, Inc. 11,564 510,551
Rohm & Haas Co. 8,040 355,609
-------------
6,393,063
-------------
</Table>
The accompanying notes are an integral part of the financial statements.
7
<Page>
<Table>
<Caption>
NUMBER OF MARKET
SHARES VALUE
----------- -------------
COMMERCIAL SERVICES -- 2.0%
Allied Waste
Industries, Inc.* 11,360 $ 105,421
Apollo Group, Inc. Cl. A* 6,588 531,717
Block (H&R), Inc.+ 5,874 287,826
Cendant Corp. 37,842 884,746
Cintas Corp. 6,190 271,493
Convergys Corp.* 5,116 76,689
Donnelley (R.R.) &
Sons Co. 7,822 276,038
eBay, Inc.* 23,720 2,758,162
Ecolab, Inc.+ 9,216 323,758
Equifax, Inc. 4,859 136,538
Fluor Corp.+ 2,927 159,551
Moody's Corp. 5,246 455,615
Paychex, Inc. 13,497 459,978
PerkinElmer, Inc. 4,608 103,634
Quest Diagnostics, Inc. 3,664 350,095
Robert Half
International, Inc. 6,280 184,820
Ryder System, Inc. 2,382 113,788
Waste Management, Inc. 20,753 621,345
------------
8,101,214
------------
COMMUNICATIONS -- 2.2%
ADC
Telecommunications, Inc.* 27,448 73,561
Andrew Corp.* 5,761 78,522
Avaya, Inc.* + 16,176 278,227
Ciena Corp.* 19,241 64,265
Citizens
Communications Co. 12,201 168,252
L-3 Communications
Holdings, Inc. 3,800 278,312
Lucent
Technologies, Inc.* + 153,879 578,585
Network
Appliance, Inc.* + 12,820 425,880
Nextel Communications,
Inc. Cl. A* 39,730 1,191,900
Qualcomm, Inc. 58,160 2,465,984
SBC Communications, Inc. 118,546 3,054,930
Scientific-Atlanta, Inc. 5,510 181,885
Tellabs, Inc.* 14,912 128,094
------------
8,968,397
------------
COMMUNICATIONS EQUIPMENT -- 0.4%
Motorola, Inc. 86,010 1,479,372
------------
COMPUTER INTEGRATED SYSTEMS DESIGN -- 0.4%
Autodesk, Inc. 8,180 310,431
Computer Sciences Corp.* 6,787 382,583
Parametric
Technology Corp.* 9,034 53,210
Sun Microsystems, Inc.* 118,808 639,187
Teradyne, Inc.* 6,960 $ 118,807
Unisys Corp.* 11,915 121,295
------------
1,625,513
------------
COMPUTER PROGRAMMING SERVICES -- 0.0%
Mercury
Interactive Corp.* + 3,370 153,503
------------
COMPUTERS & INFORMATION -- 4.4%
Apple Computer, Inc.* 13,826 890,394
Cisco Systems, Inc.* 234,773 4,531,119
Comverse
Technology, Inc.* 7,022 171,688
Dell, Inc.* 88,547 3,731,371
EMC Corp.* 85,932 1,277,809
Gateway, Inc.* 12,490 75,065
International Business
Machines Corp. 59,344 5,850,132
International
Game Technology 12,316 423,424
Jabil Circuit, Inc.* + 7,178 183,613
Lexmark
International, Inc.* 4,664 396,440
Solectron Corp.* 34,381 183,251
Symbol
Technologies, Inc.+ 8,535 147,655
------------
17,861,961
------------
COMPUTERS & OFFICE EQUIPMENT -- 0.9%
Electronic Data
Systems Corp. 17,871 412,820
Hewlett-Packard Co. 107,815 2,260,881
Pitney Bowes, Inc. 8,302 384,217
Xerox Corp.* 34,014 578,578
------------
3,636,496
------------
CONTAINERS -- 0.2%
Ball Corp. 4,020 176,800
Bemis Co., Inc. 3,866 112,462
Pactiv Corp.* 5,359 135,529
Sealed Air Corp.* 2,991 159,331
Temple-Inland, Inc. 2,038 139,399
------------
723,521
------------
COSMETICS & PERSONAL CARE -- 2.3%
Alberto-Culver Co. 3,207 155,764
Avon Products, Inc. 16,956 656,197
Colgate-Palmolive Co. 18,977 970,863
The Gillette Co. 35,783 1,602,363
Kimberly-Clark Corp. 17,703 1,165,034
The Procter & Gamble Co. 90,408 4,979,673
------------
9,529,894
------------
DATA PROCESSING & PREPARATION -- 0.8%
Affiliated Computer
Services, Inc. Cl. A* + 4,600 276,874
Automatic Data
Processing, Inc. 20,904 $ 927,092
First Data Corp. 29,533 1,256,334
Fiserv, Inc.* 7,021 282,174
IMS Health, Inc. 8,324 193,200
NCR Corp.* 3,350 231,920
------------
3,167,594
------------
ELECTRIC UTILITIES -- 2.7%
AES Corp.* 23,449 320,548
Allegheny Energy, Inc.* + 5,020 98,944
Ameren Corp.+ 6,481 324,957
American Electric
Power Co.+ 14,257 489,585
Calpine Corp.* + 20,471 80,656
CenterPoint Energy, Inc.+ 11,363 128,402
Cinergy Corp. 6,563 273,218
CMS Energy Corp.* + 5,538 57,872
Consolidated Edison, Inc.+ 8,750 382,812
Constellation Energy
Group, Inc. 5,925 258,982
Dominion Resources, Inc. 11,878 804,616
DTE Energy Co.+ 6,037 260,376
Duke Energy Corp. 33,635 851,975
Edison International 11,730 375,712
Entergy Corp. 8,160 551,534
Exelon Corp.+ 23,636 1,041,639
FirstEnergy Corp. 11,857 468,470
FPL Group, Inc.+ 6,686 499,778
NiSource, Inc. 9,446 215,180
PG&E Corp.* 14,421 479,931
Pinnacle West
Capital Corp. 3,200 142,112
PPL Corp. 6,689 356,390
Progress Energy, Inc.+ 8,872 401,369
Public Service Enterprise
Group, Inc.+ 8,598 445,118
Southern Co.+ 26,487 887,844
Teco Energy, Inc.+ 7,361 112,918
TXU Corp.+ 8,777 566,643
------------
10,877,581
------------
ELECTRICAL EQUIPMENT & ELECTRONICS -- 6.8%
Advanced Micro
Devices, Inc.* + 12,760 280,975
Altera Corp.* 13,320 275,724
American Power
Conversion Corp. 7,130 152,582
Analog Devices, Inc. 13,570 501,004
Applied Micro
Circuits Corp.* 10,300 43,363
Broadcom Corp. Cl. A* 11,553 372,931
Emerson Electric Co. 14,957 1,048,486
Freescale Semiconductor,
Inc. Cl. B* 14,325 263,007
</Table>
The accompanying notes are an integral part of the financial statements.
8
<Page>
<Table>
<Caption>
NUMBER OF MARKET
SHARES VALUE
----------- -------------
General Electric Co. 377,093 $ 13,763,894
Intel Corp. 225,402 5,272,153
JDS Uniphase Corp.* + 51,388 162,900
Johnson Controls, Inc. 6,750 428,220
Kla-Tencor Corp.* + 7,006 326,339
Linear Technology Corp. 11,030 427,523
LSI Logic Corp.* 13,828 75,777
Maxim Integrated
Products, Inc. 11,660 494,267
Micron
Technology, Inc.* + 21,917 270,675
Molex, Inc.+ 6,790 203,700
National
Semiconductor Corp. 12,896 231,483
Novellus Systems, Inc. 5,150 143,633
Nvidia Corp.* 6,000 141,360
PMC-Sierra, Inc.* 6,189 69,626
Power-One, Inc.* 3,020 26,938
Qlogic Corp.* 3,300 121,209
Rockwell Automation, Inc. 6,568 325,444
Sanmina-SCI Corp.* + 18,652 157,982
Texas Instruments, Inc. 61,926 1,524,618
Xilinx, Inc. 12,411 367,986
-------------
27,473,799
-------------
ENERGY -- 7.2%
Amerada Hess Corp. 3,253 267,982
Anadarko Petroleum Corp. 8,922 578,235
Apache Corp. 11,700 591,669
BJ Services Co. 5,800 269,932
Burlington Resources, Inc. 14,200 617,700
ChevronTexaco Corp. 75,544 3,966,815
ConocoPhillips 24,664 2,141,575
Devon Energy Corp. 17,370 676,040
Dynegy, Inc. Cl. A* + 14,427 66,653
El Paso Corp. 22,846 237,598
EOG Resources, Inc. 4,200 299,712
Exxon Mobil Corp. 229,934 11,786,417
Halliburton Co. 15,765 618,619
Kerr-McGee Corp. 5,446 314,724
KeySpan Corp. 5,780 228,021
Kinder Morgan, Inc. 4,390 321,041
Marathon Oil Corp. 12,405 466,552
Nabors Industries Limited* 5,315 272,606
Nicor, Inc.+ 1,589 58,698
Noble Corp.* 4,840 240,742
Occidental Petroleum Corp. 14,004 817,273
Peoples Energy Corp. 1,357 59,640
Rowan Companies, Inc.* 3,821 98,964
Schlumberger Limited 21,139 1,415,256
Sempra Energy+ 8,317 305,068
Sunoco, Inc. 2,693 220,045
Transocean, Inc.* + 11,527 488,630
Unocal Corp. 9,457 $ 408,921
Valero Energy Corp. 9,100 413,140
The Williams
Companies, Inc. 19,818 322,835
Xcel Energy, Inc. 14,472 263,390
XTO Energy, Inc. 9,300 329,034
-------------
29,163,527
-------------
ENTERTAINMENT & LEISURE -- 1.0%
Brunswick Corp. 3,239 160,330
Harrah's
Entertainment, Inc.+ 4,023 269,098
News Corp., Inc. Cl. A+ 92,200 1,720,452
The Walt Disney Co. 73,422 2,041,132
-------------
4,191,012
-------------
FINANCIAL SERVICES -- 3.9%
American Express Co. 44,772 2,523,798
Apartment Investment &
Management Co. Cl. A 3,400 131,036
Archstone-Smith Trust 6,200 237,460
Bear Stearns
Companies, Inc. 3,718 380,389
CIT Group, Inc. 7,500 343,650
Countrywide
Financial Corp. 20,154 745,900
E Trade Financial Corp.* 13,300 198,835
Federated Investors,
Inc. Cl. B 3,900 118,560
Franklin Resources, Inc. 8,928 621,835
The Goldman Sachs
Group, Inc. 17,325 1,802,493
Huntington
Bancshares, Inc.+ 8,234 204,039
Janus Capital Group, Inc. 8,550 143,725
Lehman Brothers
Holdings, Inc. 9,672 846,107
MBNA Corp. 45,621 1,286,056
Merrill Lynch & Co., Inc. 33,169 1,982,511
Morgan Stanley 39,191 2,175,884
PNC Financial Services
Group, Inc. 10,049 577,215
Price (T. Rowe)
Group, Inc. 4,500 279,900
ProLogis Trust 6,500 281,645
The Schwab
(Charles) Corp.+ 48,761 583,182
Simon Property
Group, Inc. 7,700 497,959
-------------
15,962,179
-------------
FOODS -- 1.9%
Archer-Daniels-Midland Co. 23,261 518,953
Campbell Soup Co. 14,702 439,443
ConAgra Foods, Inc. 18,872 $ 555,780
General Mills, Inc.+ 13,008 646,628
Heinz (H. J.) Co. 12,522 488,233
Hershey Foods Corp. 8,844 491,196
Kellogg Co. 14,764 659,360
The Kroger Co.* + 26,418 463,372
McCormick & Co., Inc. 4,900 189,140
Safeway, Inc.* 15,960 315,050
Sara Lee Corp. 28,365 684,731
Starbucks Corp.* 14,230 887,383
SuperValu, Inc. 4,821 166,421
Sysco Corp.+ 22,830 871,421
Wrigley (Wm.) Jr. Co. 8,034 555,872
-------------
7,932,983
-------------
FOREST PRODUCTS & PAPER -- 0.5%
Georgia-Pacific Corp. 9,270 347,440
International Paper Co. 17,389 730,338
MeadWestvaco Corp. 7,201 244,042
OfficeMax, Inc. 3,142 98,596
Plum Creek Timber
Co., Inc. 6,600 253,704
Weyerhaeuser Co. 8,490 570,698
-------------
2,244,818
-------------
HEALTHCARE -- 1.1%
Caremark Rx, Inc.* 16,600 654,538
Express Scripts, Inc.* 2,800 214,032
HCA, Inc. 14,976 598,441
Health Management
Associates, Inc. Cl. A 8,700 197,664
Humana, Inc.* 5,703 169,322
Laboratory Corp. of
America Holdings* 5,000 249,100
Manor Care, Inc. 3,132 110,967
Tenet Healthcare Corp.* + 16,659 182,916
UnitedHealth Group, Inc. 23,240 2,045,817
-------------
4,422,797
-------------
HOME CONSTRUCTION, FURNISHINGS &
APPLIANCES -- 0.3%
Centex Corp.+ 4,446 264,893
KB Home 1,671 174,452
Leggett & Platt, Inc. 6,850 194,745
Maytag Corp.+ 2,786 58,785
Pulte Homes, Inc. 4,522 288,504
Whirlpool Corp.+ 2,369 163,958
-------------
1,145,337
-------------
HOUSEHOLD PRODUCTS -- 0.6%
Black & Decker Corp.+ 2,950 260,573
The Clorox Co. 5,470 322,347
Corning, Inc.* 49,791 586,040
Fortune Brands, Inc. 5,180 399,792
Newell Rubbermaid, Inc. 9,835 237,909
</Table>
The accompanying notes are an integral part of the financial statements.
9
<Page>
<Table>
<Caption>
NUMBER OF MARKET
SHARES VALUE
----------- -------------
Sherwin-Williams Co. 5,129 $ 228,907
Snap-On, Inc. 2,153 73,977
The Stanley Works+ 3,005 147,215
-------------
2,256,760
-------------
INDUSTRIAL - DISTRIBUTION -- 0.1%
Grainger (W.W.), Inc. 3,332 221,978
-------------
INDUSTRIAL - DIVERSIFIED -- 1.9%
3M Co. 27,972 2,295,662
Cooper Industries
Limited Cl. A 3,414 231,776
Danaher Corp. 11,010 632,084
Eaton Corp. 5,394 390,310
Illinois Tool Works, Inc. 10,543 977,125
ITT Industries, Inc. 3,337 281,810
Textron, Inc. 4,932 363,982
Tyco International Limited 71,874 2,568,777
-------------
7,741,526
-------------
INFORMATION RETRIEVAL SERVICES -- 0.4%
Yahoo!, Inc.* 48,816 1,839,387
-------------
INSURANCE -- 5.0%
ACE Limited 10,200 436,050
Aetna, Inc. 5,249 654,813
AFLAC, Inc. 18,120 721,901
Allstate Corp. 24,804 1,282,863
Ambac Financial
Group, Inc. 3,875 318,254
American International
Group, Inc. 93,070 6,111,907
Aon Corp. 11,246 268,330
Chubb Corp. 6,873 528,534
Cigna Corp. 4,940 402,956
Cincinnati Financial Corp. 6,083 269,234
The Hartford Financial
Services Group, Inc.+ 10,558 731,775
Jefferson-Pilot Corp. 4,920 255,643
Lincoln National Corp. 6,341 295,998
Loews Corp. 6,658 468,057
Marsh & McLennan
Companies, Inc. 18,642 613,322
MBIA, Inc.+ 5,175 327,474
Metlife, Inc. 26,832 1,086,964
MGIC Investment Corp. 3,589 247,318
Principal Financial
Group, Inc. 11,200 458,528
Progressive Corp. 7,148 606,436
Prudential Financial, Inc. 18,600 1,022,256
Safeco Corp. 4,559 238,162
St. Paul
Travelers Companies 23,963 888,308
Torchmark Corp. 3,926 224,332
UnumProvident Corp. 10,670 191,420
WellPoint, Inc.* 10,603 $ 1,219,345
XL Capital Limited Cl. A+ 5,027 390,347
-------------
20,260,527
-------------
LODGING -- 0.3%
Hilton Hotels Corp. 13,791 313,607
Marriott International,
Inc. Cl. A 8,164 514,169
Starwood Hotels &
Resorts Worldwide, Inc. 7,440 434,496
-------------
1,262,272
-------------
MACHINERY & COMPONENTS -- 0.9%
Baker Hughes, Inc. 11,898 507,688
Caterpillar, Inc. 12,252 1,194,693
Cummins, Inc. 1,539 128,953
Deere & Co. 8,843 657,919
Dover Corp. 7,335 307,630
Ingersoll-Rand Co. Cl. A 6,283 504,525
Pall Corp.+ 4,592 132,938
Parker-Hannifin Corp. 4,314 326,742
-------------
3,761,088
-------------
MANUFACTURING -- 0.4%
American Standard
Companies, Inc.* 7,700 318,164
Applied Materials, Inc.* 60,706 1,038,073
Avery Dennison Corp. 3,928 235,562
Millipore Corp.* + 1,815 90,405
-------------
1,682,204
-------------
MEDICAL SUPPLIES -- 2.4%
Agilent Technologies, Inc.* 17,383 418,930
Allergan, Inc. 4,707 381,596
Applied Biosystems
Group-Applera Corp. 7,238 151,347
Bard (C.R.), Inc. 3,720 238,006
Bausch & Lomb, Inc. 1,892 121,958
Baxter International, Inc. 21,992 759,604
Becton, Dickinson & Co. 8,948 508,246
Biomet, Inc. 9,055 392,896
Boston Scientific Corp.* 30,122 1,070,837
Fisher
Scientific International* 4,100 255,758
Guidant Corp. 11,188 806,655
Medtronic, Inc. 43,181 2,144,800
St. Jude Medical, Inc.* 12,644 530,163
Stryker Corp. 14,300 689,975
Tektronix, Inc. 3,120 94,255
Thermo Electron Corp.* 5,854 176,732
Waters Corp.* 4,200 196,518
Zimmer Holdings, Inc.* 8,722 698,807
-------------
9,637,083
-------------
METALS & MINING -- 0.7%
Alcoa, Inc. 31,088 $ 976,785
Allegheny
Technologies, Inc. 3,144 68,130
Freeport-McMoRan Copper &
Gold, Inc. Cl. B+ 6,333 242,111
Newmont Mining Corp.+ 15,809 702,078
Nucor Corp.+ 5,712 298,966
Phelps Dodge Corp. 3,385 334,844
United States Steel Corp.+ 4,054 207,767
-------------
2,830,681
-------------
PHARMACEUTICALS -- 8.5%
Abbott Laboratories 55,798 2,602,977
AmerisourceBergen Corp. 4,076 239,180
Amgen, Inc.* 45,206 2,899,965
Biogen Idec, Inc.* + 12,037 801,785
Bristol-Myers Squibb Co. 69,542 1,781,666
Cardinal Health, Inc.+ 15,469 899,522
Chiron Corp.* + 6,660 221,978
Eli Lilly & Co. 40,380 2,291,565
Forest Laboratories, Inc.* + 13,280 595,741
Genzyme Corp.* 8,100 470,367
Gilead Sciences, Inc.* 15,344 536,887
Hospira, Inc.* 5,539 185,556
Johnson & Johnson 106,012 6,723,281
King
Pharmaceuticals, Inc.* 8,867 109,951
McKesson Corp. 10,587 333,067
Medco Health
Solutions, Inc.* 9,720 404,352
Medimmune, Inc.* 8,864 240,303
Merck & Co., Inc. 79,343 2,550,084
Mylan Laboratories, Inc.+ 9,800 173,264
Pfizer, Inc. 268,427 7,218,002
Schering-Plough Corp. 52,688 1,100,125
Sigma-Aldrich Corp. 2,484 150,183
Watson
Pharmaceutical, Inc.* 3,970 130,256
Wyeth 47,656 2,029,669
-------------
34,689,726
-------------
PHOTOGRAPHY EQUIPMENT/SUPPLIES -- 0.1%
Eastman Kodak Co.+ 10,260 330,885
-------------
PREPACKAGED SOFTWARE -- 4.2%
Adobe Systems, Inc. 8,606 539,940
BMC Software, Inc.* 8,065 150,009
Citrix Systems, Inc.* 6,092 149,437
Computer Associates
International, Inc.+ 20,923 649,868
Compuware Corp.* 13,878 89,791
Electronic Arts, Inc.* 10,900 672,312
Intuit, Inc.* 6,910 304,109
</Table>
The accompanying notes are an integral part of the financial statements.
10
<Page>
<Table>
<Caption>
NUMBER OF MARKET
SHARES VALUE
----------- -------------
Microsoft Corp. 387,528 $ 10,350,873
Novell, Inc.* 13,976 94,338
Oracle Corp.* 182,861 2,508,853
Siebel Systems, Inc.* 18,118 190,239
SunGard Data
Systems, Inc.* 10,300 291,799
Symantec Corp.* 22,600 582,176
Veritas Software Corp.* 15,546 443,838
-------------
17,017,582
-------------
REAL ESTATE -- 0.2%
Equity Office
Properties Trust 14,460 421,075
Equity Residential 10,000 361,800
-------------
782,875
-------------
RESTAURANTS -- 0.6%
Darden Restaurants, Inc. 5,692 157,896
McDonald's Corp. 44,877 1,438,757
Wendy's International, Inc. 4,075 159,984
Yum! Brands, Inc. 10,398 490,578
-------------
2,247,215
-------------
RETAIL -- 5.7%
AutoZone, Inc.* 2,954 269,730
Bed Bath & Beyond, Inc.* 10,750 428,172
Best Buy Co., Inc. 11,630 691,055
Big Lots, Inc.* 4,174 50,631
Circuit City Stores, Inc.+ 7,100 111,044
Costco Wholesale Corp. 16,442 795,957
CVS Corp. 14,303 644,636
Dillards, Inc. Cl. A 3,001 80,637
Dollar General Corp. 11,714 243,300
Family Dollar Stores, Inc.+ 6,051 188,973
Federated Department
Stores, Inc. 6,063 350,381
The Home Depot, Inc. 78,437 3,352,397
J.C. Penney Co., Inc. 10,309 426,793
Kohl's Corp.* 12,223 601,005
Lowe's Companies, Inc. 27,882 1,605,724
The May Department
Stores Co. 10,432 306,701
Office Depot, Inc.* 11,265 195,560
RadioShack Corp. 5,705 187,580
Sears, Roebuck and Co. 7,629 389,308
Staples, Inc. 17,773 599,128
Target Corp. 32,268 1,675,677
Tiffany & Co. 5,192 165,988
TJX Companies, Inc.+ 17,476 439,172
Toys R Us, Inc.* 7,662 156,841
Walgreen Co. 36,604 1,404,495
Wal-Mart Stores, Inc. 150,912 7,971,172
-------------
23,332,057
-------------
RETAIL - GROCERY -- 0.1%
Albertson's, Inc.+ 13,147 $ 313,950
-------------
TELEPHONE UTILITIES -- 2.2%
Alltel Corp. 10,967 644,421
AT&T Corp. 28,684 546,717
BellSouth Corp. 65,520 1,820,801
CenturyTel, Inc. 4,931 174,903
Qwest Communications
International, Inc.* 66,058 293,298
Sprint Corp. (FON Group) 52,135 1,295,555
Verizon
Communications, Inc. 99,029 4,011,665
-------------
8,787,360
-------------
TOBACCO -- 1.3%
Altria Group, Inc. 73,429 4,486,512
Reynolds American, Inc.+ 5,400 424,440
UST, Inc. 6,022 289,718
-------------
5,200,670
-------------
TOYS, GAMES -- 0.1%
Hasbro, Inc. 6,391 123,858
Mattel, Inc. 14,889 290,187
-------------
414,045
-------------
TRANSPORTATION -- 1.9%
Burlington Northern
Santa Fe Corp. 13,286 628,561
Carnival Corp. 22,585 1,301,574
CSX Corp. 7,665 307,213
FedEx Corp. 10,803 1,063,987
Norfolk Southern Corp. 14,089 509,881
Union Pacific Corp. 9,217 619,843
United Parcel Service,
Inc. Cl. B 39,900 3,409,854
-------------
7,840,913
-------------
TRAVEL -- 0.0%
Sabre Holdings Corp. 4,931 109,271
-------------
TOTAL EQUITIES
(COST $373,180,319) 403,171,478
-------------
<Caption>
PRINCIPAL
AMOUNT
-----------
SHORT-TERM INVESTMENTS -- 7.5%
CASH EQUIVALENTS -- 6.9%**
American AAdvanage
Select Money
Market Fund 325,065 325,065
Bank of America
Bank Note
2.260% 02/15/2005 $ 242,843 242,843
Bank of America
Bank Note
2.270% 01/18/2005 $ 566,633 $ 566,633
Bank of America
Bank Note
2.270% 03/03/2005 1,052,318 1,052,318
Bank of America
Bank Note
2.300% 06/09/2005 566,633 566,633
Bank of Montreal
Eurodollar Time Deposit
2.125% 02/02/2005 246,890 246,890
Bank of Montreal
Eurodollar Time Deposit
2.260% 01/28/2005 256,537 256,537
BGI Institutional Money
Market Fund 2,914,112 2,914,112
BNP Paribas
Eurodollar Time Deposit
2.300% 01/03/2005 161,895 161,895
Calyon
Eurodollar Time Deposit
2.435% 03/16/2005 692,911 692,911
Canadian Imperial Bank
of Commerce Bank Note
2.030% 05/18/2005 1,618,951 1,618,951
Citigroup
Eurodollar Time Deposit
2.080% 01/28/2005 635,438 635,438
Den Danske Bank
Eurodollar Time Deposit
2.260% 01/20/2005 971,371 971,371
Dexia Group
Eurodollar Time Deposit
2.040% 01/21/2005 323,790 323,790
Federal Home Loan Bank
Discount Note
2.184% 01/05/2005 1,005,605 1,005,605
Fortis Bank
Eurodollar Time Deposit
2.140% 01/12/2005 323,790 323,790
Fortis Bank
Eurodollar Time Deposit
2.200% 02/11/2005 242,843 242,843
Fortis Bank
Eurodollar Time Deposit
2.260% 01/05/2005 1,335,635 1,335,635
Freddie Mac
Discount Note
2.184% 01/04/2005 1,131,413 1,131,413
Freddie Mac
Discount Note
2.228% 02/01/2005 302,051 302,051
</Table>
The accompanying notes are an integral part of the financial statements.
11
<Page>
<Table>
<Caption>
PRINCIPAL MARKET
AMOUNT VALUE
----------- -------------
Freddie Mac
Discount Note
2.277% 02/01/2005 $ 1,413,534 $ 1,413,534
General Electric
Capital Corp.
2.294% 01/21/2005 460,969 460,969
General Electric
Capital Corp.
2.295% 01/10/2005 788,681 788,681
HBOS Halifax Bank
of Scotland
Eurodollar Time Deposit
2.025% 01/21/2005 372,359 372,359
Lloyds TSB Bank
Eurodollar Time Deposit
2.280% 02/02/2005 396,643 396,643
Merrill Lynch Premier
Institutional Money
Market Fund 534,256 534,256
Merrimac Cash Fund,
Premium Class 1,214,213 1,214,213
Morgan Stanley Dean
Witter & Co.
2.393% 07/19/2005 1,068,508 1,068,508
Royal Bank of Canada
Eurodollar Time Deposit
2.250% 01/19/2005 809,476 809,476
Royal Bank of Canada
Eurodollar Time Deposit
2.260% 02/01/2005 647,580 647,580
Royal Bank of Scotland
Eurodollar Time Deposit
2.015% 01/21/2005 934,135 934,135
Royal Bank of Scotland
Eurodollar Time Deposit
2.270% 02/02/2005 485,685 485,685
Royal Bank of Scotland
Eurodollar Time Deposit
2.360% 02/17/2005 80,948 80,948
Toronto Dominion Bank
Eurodollar Time Deposit
2.420% 03/01/2005 809,476 809,476
Wells Fargo
Eurodollar Time Deposit
2.270% 01/25/2005 202,369 202,369
Wells Fargo
Eurodollar Time Deposit
2.310% 01/28/2005 809,476 809,476
Wells Fargo
Eurodollar Time Deposit
2.320% 01/14/2005 1,939,503 1,939,503
-------------
27,884,535
-------------
REPURCHASE AGREEMENT -- 0.5%
Investors Bank & Trust
Company Repurchase
Agreement, dated
12/31/2004, 1.75%,
due 01/03/2005(a) $ 2,030,018 $ 2,030,018
-------------
U.S. TREASURY BILLS -- 0.1%
U.S. Treasury Bill
2.140% 03/24/2005 385,000 383,152
-------------
TOTAL SHORT-TERM
INVESTMENTS
(COST $30,297,676) 30,297,705
-------------
TOTAL INVESTMENTS -- 106.7%
(COST $403,477,995)*** 433,469,183
OTHER ASSETS/
(LIABILITIES) -- (6.7%) (27,132,777)
-------------
NET ASSETS -- 100.0% $ 406,336,406
=============
</Table>
NOTES TO PORTFOLIO OF INVESTMENTS
* Non-income producing security.
** Represents investments of security lending collateral. (NOTE 2).
*** See Note 7 for aggregate cost for Federal tax purposes.
+ Denotes all or a portion of security on loan.
(a) Maturity value of $2,030,314. Collateralized by U.S. Government Agency
obligation with a rate of 5.875%, maturity date of 5/25/2015, and an
aggregate market value, including accrued interest, of $2,131,519.
The accompanying notes are an integral part of the financial statements.
12
<Page>
MML SMALL CAP EQUITY FUND - PORTFOLIO OF INVESTMENTS
DECEMBER 31, 2004
<Table>
<Caption>
NUMBER OF MARKET
SHARES VALUE
----------- -------------
EQUITIES -- 95.3%
AIR TRANSPORTATION -- 1.1%
SkyWest, Inc.+ 56,800 $ 1,139,408
-------------
APPAREL, TEXTILES & SHOES -- 1.5%
Carter's, Inc.* + 44,900 1,526,151
-------------
BANKING, SAVINGS & LOANS -- 9.2%
Alabama National Bancorp 5,900 380,550
First Republic Bank 45,100 2,390,300
First State Bancorp 11,300 415,388
Hanmi Financial Corp. 41,300 1,484,322
Pacific Capital Bancorp 69,554 2,364,140
UMB Financial Corp. 8,400 475,944
Webster Financial Corp. 34,680 1,756,195
-------------
9,266,839
-------------
BROADCASTING, PUBLISHING & PRINTING -- 2.9%
Gray Television, Inc. 107,100 1,660,050
Lin TV Corp. Cl. A* 66,800 1,275,880
-------------
2,935,930
-------------
CHEMICALS -- 2.8%
MacDermid, Inc. 39,600 1,429,560
Spartech Corp. 52,500 1,422,225
-------------
2,851,785
-------------
COMMERCIAL SERVICES -- 6.0%
ADVO, Inc. 56,100 1,999,965
Arbitron, Inc.* 57,800 2,264,604
G&K Services, Inc. Cl. A 41,400 1,797,588
-------------
6,062,157
-------------
COMPUTER RELATED SERVICES -- 0.9%
eSpeed, Inc. Cl. A* 70,000 865,900
-------------
COSMETICS & PERSONAL CARE -- 0.6%
Revlon, Inc. Cl. A* 262,700 604,210
-------------
ELECTRICAL EQUIPMENT & ELECTRONICS -- 8.9%
Baldor Electric Co. 56,500 1,555,445
Cognex Corp. 52,800 1,473,120
Micrel, Inc.* + 136,400 1,503,128
Mykrolis Corp.* 143,400 2,031,978
Teleflex, Inc. 46,600 2,420,404
-------------
8,984,075
-------------
ENERGY -- 6.7%
Headwaters, Inc.* 45,400 1,293,900
Rowan Companies, Inc.* 36,100 934,990
St. Mary Land &
Exploration Co. 22,800 951,672
Unit Corp.* 48,500 1,853,185
W-H Energy Services, Inc.* 77,200 1,726,192
-------------
6,759,939
-------------
FINANCIAL SERVICES -- 10.5%
Chittenden Corp. 73,450 $ 2,110,219
Eaton Vance Corp. 61,500 3,207,225
Fidelity Bankshares, Inc. 37,100 1,586,396
Jefferies Group, Inc.+ 64,800 2,610,144
Piper Jaffray Cos.* 22,200 1,064,490
-------------
10,578,474
-------------
HOME CONSTRUCTION, FURNISHINGS &
APPLIANCES -- 1.8%
Fossil, Inc.* 72,350 1,855,054
-------------
HOUSEHOLD PRODUCTS -- 1.7%
Trex Company, Inc.* + 33,200 1,741,008
-------------
INDUSTRIAL - DIVERSIFIED -- 1.9%
Carlisle Companies, Inc. 29,300 1,902,156
-------------
INSURANCE -- 6.0%
The Commerce Group, Inc. 46,000 2,807,840
HCC Insurance Holdings, Inc. 50,500 1,672,560
IPC Holdings Limited 37,000 1,609,870
-------------
6,090,270
-------------
MACHINERY & COMPONENTS -- 13.1%
Actuant Corp. Cl. A* 33,500 1,747,025
Global Power Equipment
Group, Inc.* 202,800 1,995,552
Helix Technology Corp. 101,400 1,763,346
IDEX Corp. 56,300 2,280,150
Kaydon Corp.+ 74,000 2,443,480
Roper Industries, Inc. 49,200 2,989,884
-------------
13,219,437
-------------
MEDICAL SUPPLIES -- 4.5%
Coherent, Inc.* 58,900 1,792,916
Dionex Corp.* 28,500 1,615,095
Mine Safety Appliances Co. 21,900 1,110,330
-------------
4,518,341
-------------
METALS & MINING -- 0.2%
Foundation Coal
Holdings, Inc.* + 6,400 147,584
-------------
PHARMACEUTICALS -- 2.9%
Taro Pharmaceutical
Industries Limited* + 37,400 1,272,722
Valeant Pharmaceuticals
International+ 62,200 1,638,970
-------------
2,911,692
-------------
PREPACKAGED SOFTWARE -- 1.4%
Dendrite International, Inc.* 71,100 1,379,340
-------------
RESTAURANTS -- 1.3%
RARE Hospitality
International, Inc.* 42,000 $ 1,338,120
-------------
RETAIL -- 2.5%
Coldwater Creek, Inc.* 82,000 2,531,340
-------------
TELEPHONE UTILITIES -- 0.2%
Iowa Telecommunications
Services, Inc.+ 6,900 148,833
-------------
TRANSPORTATION -- 6.7%
Heartland Express, Inc. 115,415 2,593,375
Landstar System, Inc.* 37,000 2,724,680
Robinson (C.H.)
Worldwide, Inc.+ 26,700 1,482,384
-------------
6,800,439
-------------
TOTAL EQUITIES
(COST $69,160,640) 96,158,482
-------------
<Caption>
PRINCIPAL
AMOUNT
-----------
SHORT-TERM INVESTMENTS -- 17.4%
CASH EQUIVALENTS -- 12.1%**
American AAdvanage
Select Money
Market Fund 141,612 141,612
Bank of America
Bank Note
2.260% 02/15/2005 $ 105,793 105,793
Bank of America
Bank Note
2.270% 01/18/2005 246,849 246,849
Bank of America
Bank Note
2.270% 03/03/2005 458,434 458,434
Bank of America
Bank Note
2.300% 06/09/2005 246,849 246,849
Bank of Montreal
Eurodollar Time Deposit
2.125% 02/02/2005 107,556 107,556
Bank of Montreal
Eurodollar Time Deposit
2.260% 01/28/2005 111,759 111,759
BGI Institutional Money
Market Fund 1,269,510 1,269,510
BNP Paribas
Eurodollar Time Deposit
2.300% 01/03/2005 70,528 70,528
</Table>
The accompanying notes are an integral part of the financial statements.
13
<Page>
<Table>
<Caption>
PRINCIPAL MARKET
AMOUNT VALUE
----------- -------------
Calyon
Eurodollar Time Deposit
2.435% 03/16/2005 $ 301,861 $ 301,861
Canadian Imperial Bank
of Commerce Bank Note
2.030% 05/18/2005 705,283 705,283
Citigroup
Eurodollar Time Deposit
2.080% 01/28/2005 276,824 276,824
Den Danske Bank
Eurodollar Time Deposit
2.260% 01/20/2005 423,170 423,170
Dexia Group
Eurodollar Time Deposit
2.040% 01/21/2005 141,057 141,057
Federal Home Loan Bank
Discount Note
2.184% 01/05/2005 438,084 438,084
Fortis Bank
Eurodollar Time Deposit
2.140% 01/12/2005 141,057 141,057
Fortis Bank
Eurodollar Time Deposit
2.200% 02/11/2005 105,793 105,793
Fortis Bank
Eurodollar Time Deposit
2.260% 01/05/2005 581,859 581,859
Freddie Mac
Discount Note
2.184% 01/04/2005 492,891 492,891
Freddie Mac
Discount Note
2.228% 02/01/2005 131,586 131,586
Freddie Mac
Discount Note
2.277% 02/01/2005 615,795 615,795
General Electric
Capital Corp.
2.294% 01/21/2005 200,818 200,818
General Electric
Capital Corp.
2.295% 01/10/2005 343,583 343,583
HBOS Halifax
Bank of Scotland
Eurodollar Time Deposit
2.025% 01/21/2005 162,215 162,215
Lloyds TSB Bank
Eurodollar Time Deposit
2.280% 02/02/2005 172,794 172,794
Merrill Lynch Premier
Institutional Money
Market Fund 232,744 232,744
Merrimac Cash Fund,
Premium Class 528,962 528,962
Morgan Stanley
Dean Witter & Co.
2.393% 07/19/2005 $ 465,487 $ 465,487
Royal Bank of Canada
Eurodollar Time Deposit
2.250% 01/19/2005 352,642 352,642
Royal Bank of Canada
Eurodollar Time Deposit
2.260% 02/01/2005 282,113 282,113
Royal Bank of Scotland
Eurodollar Time Deposit
2.015% 01/21/2005 406,948 406,948
Royal Bank of Scotland
Eurodollar Time Deposit
2.270% 02/02/2005 211,585 211,585
Royal Bank of Scotland
Eurodollar Time Deposit
2.360% 02/17/2005 35,264 35,264
Toronto Dominion Bank
Eurodollar Time Deposit
2.420% 03/01/2005 352,642 352,642
Wells Fargo
Eurodollar Time Deposit
2.270% 01/25/2005 88,160 88,160
Wells Fargo
Eurodollar Time Deposit
2.310% 01/28/2005 352,642 352,642
Wells Fargo
Eurodollar Time Deposit
2.320% 01/14/2005 844,929 844,929
-------------
12,147,678
-------------
REPURCHASE AGREEMENT -- 5.3%
Investors Bank & Trust
Company Repurchase
Agreement, dated
12/31/2004, 1.75%,
due 01/03/2005(a) 5,375,141 5,375,141
-------------
TOTAL SHORT-TERM
INVESTMENTS
(AT AMORTIZED COST) 17,522,819
-------------
TOTAL INVESTMENTS -- 112.7%
(COST $86,683,459)*** 113,681,301
OTHER ASSETS/
(LIABILITIES) -- (12.7%) (12,766,704)
-------------
NET ASSETS -- 100.0% $ 100,914,597
=============
</Table>
NOTES TO PORTFOLIO OF INVESTMENTS
* Non-income producing security.
** Represents investments of security lending collateral. (NOTE 2).
*** See Note 7 for aggregate cost for Federal tax purposes.
+ Denotes all or a portion of security on loan.
(a) Maturity value of $5,375,925. Collaterized by U.S. Government Agency
obligation with a rate of 4.126%, maturity date of 02/01/2033, and an
aggregate market value, including accrued interest, of $5,643,898.
The accompanying notes are an integral part of the financial statements.
14
<Page>
MML SERIES INVESTMENT FUND - FINANCIAL STATEMENTS
STATEMENT OF ASSETS AND LIABILITIES
DECEMBER 31, 2004
<Table>
<Caption>
MML MML
EQUITY SMALL CAP
INDEX EQUITY
FUND FUND
-------------- --------------
ASSETS:
Investments, at value (NOTE 2)(a) $ 403,171,478 $ 96,158,482
Short-term investments, at value (NOTE 2)(b) 30,297,705 17,522,819
-------------- --------------
Total Investments(c) 433,469,183 113,681,301
-------------- --------------
Cash - 1,627
Receivables from:
Investments sold 357,222 -
Fund shares sold 23,550 45,637
Interest and dividends 566,409 63,907
-------------- --------------
Total assets 434,416,364 113,792,472
-------------- --------------
LIABILITIES:
Payables for:
Investments purchased - 610,441
Fund shares repurchased 51,064 27,249
Variation margin on open futures contracts (NOTE 2) 2,750 -
Securities on loan (NOTE 2) 27,884,535 12,147,678
Directors' fees and expenses (NOTE 3) 33,144 8,726
Affiliates (NOTE 3):
Investment management fees 34,053 54,580
Administration fees 42,943 -
Accrued expenses and other liabilities 31,469 29,201
-------------- --------------
Total liabilities 28,079,958 12,877,875
-------------- --------------
NET ASSETS $ 406,336,406 $ 100,914,597
============== ==============
NET ASSETS CONSIST OF:
Paid-in capital $ 391,561,349 $ 73,993,478
Distributions in excess of net investment income (10,102) (7,904)
Accumulated net realized gain (loss) on investments and futures contracts (15,284,575) (68,819)
Net unrealized appreciation on investments and futures contracts 30,069,734 26,997,842
-------------- --------------
NET ASSETS $ 406,336,406 $ 100,914,597
============== ==============
Shares outstanding: 7,937,656
==============
Net asset value, offering price and redemption price per share: $ 12.71
==============
Class I shares:
Net assets $ 85,138,011
==============
Shares outstanding 5,712,676
==============
Net asset value, offering price and redemption price per share $ 14.90
==============
Class II shares:
Net assets $ 184,271,177
==============
Shares outstanding 12,374,179
==============
Net asset value, offering price and redemption price per share $ 14.89
==============
Class III shares:
Net assets $ 136,927,218
==============
Shares outstanding 9,213,017
==============
Net asset value, offering price and redemption price per share $ 14.86
==============
(a) Cost of investments: $ 373,180,319 $ 69,160,640
(b) Cost of short-term investments: $ 30,297,676 $ 17,522,819
(c) Securities on loan with market value of: $ 26,729,027 $ 11,715,677
</Table>
The accompanying notes are an integral part of the financial statements.
15
<Page>
STATEMENT OF OPERATIONS
FOR THE YEAR ENDED DECEMBER 31, 2004
<Table>
<Caption>
MML MML
EQUITY SMALL CAP
INDEX EQUITY
FUND FUND
-------------- --------------
INVESTMENT INCOME (NOTE 2):
Dividends(a) $ 8,067,833 $ 747,032
Interest(b) 52,528 42,120
-------------- --------------
Total investment income 8,120,361 789,152
-------------- --------------
EXPENSES (NOTE 2):
Investment management fees (NOTE 3) 401,854 580,751
Custody fees 61,689 15,952
Trustee reporting 5,039 4,411
Audit and legal fees 27,923 23,319
Proxy fees 921 126
Shareholder reporting fees 19,585 2,326
Directors' fees (NOTE 3) 36,827 8,092
Administration fees (NOTE 3):
Class I 241,990 -
Class II 350,614 -
Class III 68,329 -
-------------- --------------
Total expenses 1,214,771 634,977
Class II Administration fees waived (NOTE 3) (111,436) -
Class III Administration fees waived (NOTE 3) (68,329) -
-------------- --------------
Net expenses 1,035,006 634,977
-------------- --------------
NET INVESTMENT INCOME (LOSS) 7,085,355 154,175
-------------- --------------
REALIZED AND UNREALIZED GAIN (LOSS):
Net realized gain (loss) on:
Investment transactions (5,834,571) 2,541,228
Closed futures contracts 505,241 -
-------------- --------------
Net realized gain (loss) (5,329,330) 2,541,228
-------------- --------------
Net change in unrealized appreciation (depreciation) on:
Investments 38,250,052 11,469,589
Open futures contracts (10,845) -
-------------- --------------
Net unrealized gain 38,239,207 11,469,589
-------------- --------------
NET REALIZED AND UNREALIZED GAIN 32,909,877 14,010,817
-------------- --------------
NET INCREASE IN NET ASSETS RESULTING FROM OPERATIONS $ 39,995,232 $ 14,164,992
============== ==============
(a) Net of withholding tax of: $ - $ -
(b) Including securities lending income of: $ 19,210 $ 6,137
</Table>
The accompanying notes are an integral part of the financial statements.
16
<Page>
STATEMENTS OF CHANGES IN NET ASSETS
<Table>
<Caption>
MML EQUITY INDEX FUND
-------------------------------------
YEAR YEAR
ENDED ENDED
DECEMBER 31, 2004 DECEMBER 31, 2003
----------------- -----------------
INCREASE (DECREASE) IN NET ASSETS:
OPERATIONS:
Net investment income $ 7,085,355 $ 5,321,954
Net realized gain (loss) on investment transactions and
futures contracts (5,329,330) (2,518,982)
Net change in unrealized appreciation on investments and
futures contracts 38,239,207 84,005,759
----------------- -----------------
NET INCREASE IN NET ASSETS RESULTING FROM OPERATIONS 39,995,232 86,808,731
DISTRIBUTIONS TO SHAREHOLDERS (NOTE 2):
From net investment income - -
Class I (1,343,883) (913,733)
Class II (3,190,498) (2,486,104)
Class III (2,549,489) (1,931,671)
----------------- -----------------
TOTAL DISTRIBUTIONS FROM NET INVESTMENT INCOME (7,083,870) (5,331,508)
----------------- -----------------
FROM NET REALIZED GAINS - -
----------------- -----------------
NET FUND SHARE TRANSACTIONS (NOTE 5):
Class I 1,433 4,695,413
Class II (19,877,415) 26,828,374
Class III (11,810,653) (7,355,331)
----------------- -----------------
NET FUND SHARE TRANSACTIONS (NOTE 5) (31,686,635) 24,168,456
----------------- -----------------
TOTAL INCREASE IN NET ASSETS 1,224,727 105,645,679
NET ASSETS:
Beginning of year 405,111,679 299,466,000
----------------- -----------------
End of year $ 406,336,406 $ 405,111,679
================= =================
Distributions in excess of net investment income included in
net assets at end of the year $ (10,102) $ (12,524)
================= =================
<Caption>
MML SMALL CAP EQUITY FUND
-------------------------------------
YEAR YEAR
ENDED ENDED
DECEMBER 31, 2004 DECEMBER 31, 2003
----------------- -----------------
INCREASE (DECREASE) IN NET ASSETS:
OPERATIONS:
Net investment income $ 154,175 $ 141,322
Net realized gain (loss) on investment transactions and
futures contracts 2,541,228 2,035,667
Net change in unrealized appreciation on investments and
futures contracts 11,469,589 17,469,139
----------------- -----------------
NET INCREASE IN NET ASSETS RESULTING FROM OPERATIONS 14,164,992 19,646,128
DISTRIBUTIONS TO SHAREHOLDERS (NOTE 2):
From net investment income (159,391) (142,999)
Class I - -
Class II - -
Class III - -
----------------- -----------------
TOTAL DISTRIBUTIONS FROM NET INVESTMENT INCOME (159,391) (142,999)
----------------- -----------------
FROM NET REALIZED GAINS (1,804,441) -
----------------- -----------------
NET FUND SHARE TRANSACTIONS (NOTE 5):
Class I - -
Class II - -
Class III - -
----------------- -----------------
NET FUND SHARE TRANSACTIONS (NOTE 5) 2,809,366 4,892,753
----------------- -----------------
TOTAL INCREASE IN NET ASSETS 15,010,526 24,395,882
NET ASSETS:
Beginning of year 85,904,071 61,508,189
----------------- -----------------
End of year $ 100,914,597 $ 85,904,071
================= =================
Distributions in excess of net investment income included in
net assets at end of the year $ (7,904) $ (5,072)
================= =================
</Table>
The accompanying notes are an integral part of the financial statements.
17
<Page>
FINANCIAL HIGHLIGHTS (FOR A SHARE OUTSTANDING THROUGHOUT EACH PERIOD)
<Table>
<Caption>
CLASS I
-------
YEAR ENDED YEAR ENDED YEAR ENDED YEAR ENDED YEAR ENDED
12/31/04 12/31/03 12/31/02 12/31/01 12/31/00
---------- ---------- ---------- ---------- ------------
NET ASSET VALUE, BEGINNING OF PERIOD $ 13.71 $ 10.83 $ 14.14 $ 16.27 $ 18.13
---------- ---------- ---------- ---------- ------------
INCOME (LOSS) FROM INVESTMENT OPERATIONS:
Net investment income 0.22*** 0.16*** 0.14*** 0.14*** 0.16***
Net realized and unrealized gain (loss)
on investments 1.21 2.88 (3.31) (2.14) (1.88)
---------- ---------- ---------- ---------- ------------
Total income (loss) from investment
operations 1.43 3.04 (3.17) (2.00) (1.72)
---------- ---------- ---------- ---------- ------------
LESS DISTRIBUTIONS TO SHAREHOLDERS:
From net investment income (0.24) (0.16) (0.14) (0.07) (0.14)
From net realized gains - - - (0.06) -
---------- ---------- ---------- ---------- ------------
Total distributions (0.24) (0.16) (0.14) (0.13) (0.14)
---------- ---------- ---------- ---------- ------------
NET ASSET VALUE, END OF PERIOD $ 14.90 $ 13.71 $ 10.83 $ 14.14 $ 16.27
========== ========== ========== ========== ============
TOTAL RETURN(a) 10.42% 28.08% (22.46)% (12.32)% (9.53)%
RATIOS / SUPPLEMENTAL DATA:
Net assets, end of period (000's) $ 85,138 $ 78,597 $ 58,454 $ 81,535 $ 82,798
Ratio of expenses to average daily net assets:
Before expense waiver 0.44% 0.44% 0.44% 0.45% 0.45%
After expense waiver# N/A N/A N/A N/A 0.45%
Net investment income to average daily net assets 1.60% 1.37% 1.16% 0.92% 0.89%
Portfolio turnover rate 4% 5% 6% 5% 3%
</Table>
<Table>
<Caption>
CLASS II
--------
YEAR ENDED YEAR ENDED YEAR ENDED YEAR ENDED PERIOD ENDED
12/31/04 12/31/03 12/31/02 12/31/01 12/31/00+
---------- ---------- ---------- ---------- ------------
NET ASSET VALUE, BEGINNING OF PERIOD $ 13.70 $ 10.82 $ 14.13 $ 16.26 $ 17.96
---------- ---------- ---------- ---------- ------------
INCOME (LOSS) FROM INVESTMENT OPERATIONS:
Net investment income 0.25*** 0.19*** 0.17*** 0.16*** 0.13***
Net realized and unrealized gain (loss)
on investments 1.20 2.87 (3.32) (2.14) (1.68)
---------- ---------- ---------- ---------- ------------
Total income (loss) from investment
operations 1.45 3.06 (3.15) (1.98) (1.55)
---------- ---------- ---------- ---------- ------------
LESS DISTRIBUTIONS TO SHAREHOLDERS:
From net investment income (0.26) (0.18) (0.16) (0.09) (0.15)
From net realized gains - - - (0.06) -
---------- ---------- ---------- ---------- ------------
Total distributions (0.26) (0.18) (0.16) (0.15) (0.15)
---------- ---------- ---------- ---------- ------------
NET ASSET VALUE, END OF PERIOD $ 14.89 $ 13.70 $ 10.82 $ 14.13 $ 16.26
========== ========== ========== ========== ============
TOTAL RETURN(a) 10.60% 28.31% (22.29)% (12.18)% (8.63)%**
RATIOS / SUPPLEMENTAL DATA:
Net assets, end of period (000's) $ 184,271 $ 188,869 $ 125,942 $ 74,636 $ 56,998
Ratio of expenses to average daily net assets:
Before expense waiver 0.33% 0.33% 0.33% 0.34% 0.34%*
After expense waiver## 0.27% 0.25% 0.26% 0.29% 0.29%*
Net investment income to average daily net assets 1.75% 1.56% 1.37% 1.08% 1.10%*
Portfolio turnover rate 4% 5% 6% 5% 3%**
</Table>
* ANNUALIZED.
** PERCENTAGE REPRESENTS RESULTS FOR THE PERIOD AND ARE NOT ANNUALIZED.
*** PER SHARE AMOUNT CALCULATED ON THE AVERAGE SHARES METHOD.
+ FOR THE PERIOD FROM MAY 1, 2000 (COMMENCEMENT OF OPERATIONS) THROUGH
DECEMBER 31, 2000.
# COMPUTED AFTER GIVING EFFECT TO AN AGREEMENT BY MASSMUTUAL TO WAIVE CERTAIN
FEES AND EXPENSES OF THE FUND FOR THE YEAR ENDED DECEMBER 31, 2000.
## COMPUTED AFTER GIVING EFFECT TO AN AGREEMENT BY MASSMUTUAL TO WAIVE CERTAIN
FEES AND EXPENSES OF THE FUND FOR THE PERIOD MAY 1, 2000 THROUGH DECEMBER
31, 2000, THE YEARS ENDED DECEMBER 31, 2001, 2002, 2003 AND 2004.
(a) TOTAL RETURN INFORMATION SHOWN IN THE FINANCIAL HIGHLIGHTS TABLE DOES NOT
REFLECT EXPENSES THAT APPLY AT THE SEPARATE ACCOUNT LEVEL OR TO RELATED
INSURANCE PRODUCTS. INCLUSION OF THESE CHARGES WOULD REDUCE THE TOTAL RETURN
FIGURES FOR ALL PERIODS SHOWN.
The accompanying notes are an integral part of the financial statements.
18
<Page>
<Table>
<Caption>
CLASS III
---------
YEAR ENDED YEAR ENDED YEAR ENDED YEAR ENDED PERIOD ENDED
12/31/04 12/31/03 12/31/02 12/31/01 12/31/00+
---------- ---------- ---------- ---------- ------------
NET ASSET VALUE, BEGINNING OF PERIOD $ 13.67 $ 10.80 $ 14.10 $ 16.27 $ 17.96
---------- ---------- ---------- ---------- ------------
INCOME (LOSS) FROM INVESTMENT OPERATIONS:
Net investment income 0.26*** 0.20*** 0.18*** 0.19*** 0.15***
Net realized and unrealized gain (loss)
on investments 1.21 2.86 (3.31) (2.19) (1.67)
---------- ---------- ---------- ---------- ------------
Total income (loss) from investment
operations 1.47 3.06 (3.13) (2.00) (1.52)
---------- ---------- ---------- ---------- ------------
LESS DISTRIBUTIONS TO SHAREHOLDERS:
From net investment income (0.28) (0.19) (0.17) (0.11) (0.17)
From net realized gains - - - (0.06) -
---------- ---------- ---------- ---------- ------------
Total distributions (0.28) (0.19) (0.17) (0.17) (0.17)
---------- ---------- ---------- ---------- ------------
NET ASSET VALUE, END OF PERIOD $ 14.86 $ 13.67 $ 10.80 $ 14.10 $ 16.27
========== ========== ========== ========== ============
TOTAL RETURN(a) 10.77% 28.38% (22.18)% (12.30)% (8.50)%**
RATIOS / SUPPLEMENTAL DATA:
Net assets, end of period (000's) $ 136,927 $ 137,646 $ 115,070 $ 154,588 $ 34,111
Ratio of expenses to average daily net assets:
Before expense waiver 0.19% 0.19% 0.19% 0.20% 0.20%*
After expense waiver## 0.14% 0.14% 0.14% 0.15% 0.15%*
Net investment income to average daily net assets 1.88% 1.67% 1.46% 1.32% 1.25%*
Portfolio turnover rate 4% 5% 6% 5% 3%**
</Table>
* ANNUALIZED.
** PERCENTAGE REPRESENTS RESULTS FOR THE PERIOD AND ARE NOT ANNUALIZED.
*** PER SHARE AMOUNT CALCULATED ON THE AVERAGE SHARES METHOD.
+ FOR THE PERIOD FROM MAY 1, 2000 (COMMENCEMENT OF OPERATIONS) THROUGH
DECEMBER 31, 2000.
## COMPUTED AFTER GIVING EFFECT TO AN AGREEMENT BY MASSMUTUAL TO WAIVE CERTAIN
FEES AND EXPENSES OF THE FUND FOR THE PERIOD MAY 1, 2000 THROUGH DECEMBER
31, 2000, THE YEARS ENDED DECEMBER 31, 2001, 2002, 2003 AND 2004.
(a) TOTAL RETURN INFORMATION SHOWN IN THE FINANCIAL HIGHLIGHTS TABLE DOES NOT
REFLECT EXPENSES THAT APPLY AT THE SEPARATE ACCOUNT LEVEL OR TO RELATED
INSURANCE PRODUCTS. INCLUSION OF THESE CHARGES WOULD REDUCE THE TOTAL RETURN
FIGURES FOR ALL PERIODS SHOWN.
The accompanying notes are an integral part of the financial statements.
19
<Page>
<Table>
<Caption>
YEAR ENDED YEAR ENDED YEAR ENDED YEAR ENDED YEAR ENDED
12/31/04 12/31/03 12/31/02 12/31/01 12/31/00
---------- ---------- ---------- ---------- ------------
NET ASSET VALUE, BEGINNING OF YEAR $ 11.14 $ 8.50 $ 9.67 $ 9.40 $ 8.34
---------- ---------- ---------- ---------- ------------
INCOME (LOSS) FROM INVESTMENT OPERATIONS:
Net investment income 0.02 0.02 0.02 0.05 0.08
Net realized and unrealized gain (loss)
on investments 1.80 2.64 (1.17) 0.27 1.06
---------- ---------- ---------- ---------- ------------
Total income (loss) from investment
operations 1.82 2.66 (1.15) 0.32 1.14
---------- ---------- ---------- ---------- ------------
LESS DISTRIBUTIONS TO SHAREHOLDERS:
From net investment income (0.02) (0.02) (0.02) (0.05) (0.08)
From net realized gains (0.23) - - - -
---------- ---------- ---------- ---------- ------------
Total distributions (0.25) (0.02) (0.02) (0.05) (0.08)
---------- ---------- ---------- ---------- ------------
NET ASSET VALUE, END OF YEAR $ 12.71 $ 11.14 $ 8.50 $ 9.67 $ 9.40
========== ========== ========== ========== ============
TOTAL RETURN(a) 16.36% 31.29% (11.84)% 3.36% 13.63%
RATIOS / SUPPLEMENTAL DATA:
Net assets, end of year (000's) $ 100,915 $ 85,904 $ 61,508 $ 57,096 $ 42,661
Ratio of expenses to average daily net assets:
Before expense waiver 0.71% 0.73% 0.77% 0.69% 0.80%
After expense waiver# N/A 0.73%(b) 0.76%(b) N/A 0.76%
Net investment income to average daily net assets 0.17% 0.20% 0.25% 0.59% 1.12%
Portfolio turnover rate 39% 43% 44% 97% 65%
</Table>
# COMPUTED AFTER GIVING EFFECT TO AN AGREEMENT BY MASSMUTUAL TO WAIVE CERTAIN
FEES AND EXPENSES OF THE FUND, FOR THE YEARS ENDED DECEMBER 31, 2000 AND
2002.
(a) TOTAL RETURN INFORMATION SHOWN IN THE FINANCIAL HIGHLIGHTS TABLE DOES NOT
REFLECT EXPENSES THAT APPLY AT THE SEPARATE ACCOUNT LEVEL OR TO RELATED
INSURANCE PRODUCTS. INCLUSION OF THESE CHARGES WOULD REDUCE THE TOTAL RETURN
FIGURES FOR ALL PERIODS SHOWN.
(b) THE FUND HAS ENTERED INTO AN AGREEMENT WITH CERTAIN BROKERS TO REBATE A
PORTION OF BROKERAGE COMMISSIONS. THE REBATED COMMISSIONS ARE USED TO REDUCE
OPERATING EXPENSES OF THE FUND.
The accompanying notes are an integral part of the financial statements.
20
<Page>
NOTES TO FINANCIAL STATEMENTS
1. THE FUND
MML Series Investment Fund ("MML Trust") is registered under the Investment
Company Act of 1940, as amended (the "1940 Act"), as a no-load, open end
management investment company. The Trust is organized under the laws of the
Commonwealth of Massachusetts as a Massachusetts business trust pursuant to an
Agreement and Declaration of Trust dated May 14, 1993, as amended. The following
are two series of the Trust (each individually referred to as a "Fund" or
collectively as the "Funds"): MML Equity Index Fund ("Equity Index Fund") and
MML Small Cap Equity Fund ("Small Cap Equity Fund").
The MML Trust was established by Massachusetts Mutual Life Insurance Company
("MassMutual") for the purpose of providing vehicles for the investment of
assets of various separate investment accounts established by MassMutual and by
life insurance companies which are subsidiaries of MassMutual. Shares of MML
Trust are not offered to the general public.
The Equity Index Fund offers three classes of shares: Class I, Class II and
Class III. Each share class invests in the same portfolio of assets. The
principal difference among the classes is the level of service and
administration fees borne by the classes. Because each class will have different
fees and expenses, performance and share prices among the classes will vary. The
classes of shares are offered to different types of investors, as outlined in
the Fund's Prospectus.
2. SIGNIFICANT ACCOUNTING POLICIES
The following is a summary of significant accounting policies followed
consistently by each Fund in the preparation of the financial statements in
conformity with accounting principles generally accepted in the United States of
America ("generally accepted accounting principles"). The preparation of the
financial statements in accordance with generally accepted accounting principles
requires management to make estimates and assumptions that affect the reported
amounts and disclosures in the financial statements. Actual results could differ
from those estimates.
INVESTMENT VALUATION
Equity securities are valued on the basis of valuations furnished by a pricing
service, authorized by the Trustees, which provides the last reported sale price
for securities listed on a national securities exchange or the official closing
price on the NASDAQ National Market System, or in the case of over-the-counter
securities not so listed, the last reported bid price. Debt securities (other
than short-term obligations with a remaining maturity of sixty days or less) are
valued on the basis of valuations furnished by a pricing service, authorized by
the Trustees, which determines valuations taking into account appropriate
factors such as institutional-size trading in similar groups of securities,
yield, quality, coupon rate, maturity, type of issue, trading characteristics
and other market data. Short-term securities with a remaining maturity of sixty
days or less are valued at either amortized cost or at original cost plus
accrued interest, whichever approximates current market value. All other
securities and other assets, including debt securities for which the prices
supplied by a pricing agent are deemed by MassMutual not to be representative of
market values, including restricted securities and securities for which no
market quotation is available, are valued at fair value in accordance with
procedures approved by and determined in good faith by the Trustees, although
the actual calculation may be done by others. Securities are typically valued on
the basis of valuations furnished by a primary pricing service or, if no such
valuation is available, from a secondary pricing service. However, valuation
methods approved by the Trust's Board of Trustees which are intended to reflect
fair value may be used when pricing service information is not readily available
or when a security's value is believed to have been materially affected by a
significant event, such as a natural disaster, an economic event like a
bankruptcy filing, or a substantial fluctuation in domestic or foreign markets,
that has occurred after the close of the exchange or market on which the
security is principally traded (for example, a foreign exchange or market). In
such a case, a Fund's value for a security is likely to be different from the
last quoted market price or pricing service information. Due to the subjective
and variable nature of fair value pricing, it is possible that the value
determined for a particular asset may be materially different from the value
realized upon such asset's sale.
21
<Page>
Portfolio securities traded on more than one national securities exchange are
valued at the last price on the business day as of which such value is being
determined at the close of the exchange representing the principal market for
such securities. All assets and liabilities expressed in foreign currencies are
converted into U.S. dollars at the mean between the buying and selling rates of
such currencies against U.S. dollars last quoted by any major bank. If such
quotations are not available, the rate of exchange is determined in accordance
with policies established by the Trustees.
SECURITIES LENDING
Each Fund may lend its securities to qualified brokers; however, securities
lending cannot exceed 33% of the total assets of the Funds taken at current
value. The loans are collateralized at all times with cash or securities with a
market value at least equal to 100% of the market value of the securities on
loan. The market value of the loaned securities is determined at the close of
business of the Fund and any additional collateral is delivered to the Fund the
next business day. As with other extensions of credit, the Funds may bear the
risk of delay in recovery or even loss of rights in the collateral should the
borrower of the securities fail financially. The Funds receive compensation for
lending their securities. At December 31, 2004, the Funds loaned securities
having the following market values, collateralized by cash, which was invested
in short-term instruments in the following amounts:
<Table>
<Caption>
SECURITIES ON LOAN COLLATERAL
------------------ -------------
Equity Index Fund $ 26,729,027 $ 27,884,535
Small Cap Equity Fund 11,715,677 12,147,678
</Table>
REPURCHASE AGREEMENTS
Each Fund may enter into repurchase agreements with certain banks and
broker/dealers whereby a Fund acquires a security for cash and obtains a
simultaneous commitment from the seller to repurchase the security at an agreed
upon price and date. The Funds, through their custodian, take possession of the
securities collateralizing the repurchase agreement. The collateral is marked to
market daily to ensure that the market value of the underlying assets remains
sufficient to protect the Funds in the event of default by the seller.
Collateral for certain tri-party repurchase agreements is held at the
counterparty's custodian in a segregated account for the benefit of the Funds
and the counterparty. In connection with transactions in repurchase agreements,
if the seller defaults and the value of the collateral declines or if the seller
enters insolvency proceedings, realization of collateral by the Funds may be
delayed or limited.
ACCOUNTING FOR INVESTMENTS
Investment transactions are accounted for on the trade date. Realized gains and
losses on sales of investments and unrealized appreciation and depreciation of
investments are computed on the specific identification cost method. Interest
income, adjusted for amortization of discounts and premiums on debt securities,
is earned from the settlement date and is recorded on the accrual basis.
Dividend income is recorded on the ex-dividend date.
FEDERAL INCOME TAX
It is each Fund's intent to continue to comply with the provisions of subchapter
M of the Internal Revenue Code of 1986, as amended (the "Code"), applicable to a
regulated investment company. Under such provisions, the Funds will not be
subject to federal income taxes on their ordinary income and net realized
capital gains to the extent they are distributed or deemed to have been
distributed to their shareholders. Therefore, no Federal income tax provision is
required.
DIVIDENDS AND DISTRIBUTIONS TO SHAREHOLDERS
Dividends from net investment income and distributions of any net realized
capital gains of each Fund are declared and paid annually and at other times as
may be required to satisfy tax or regulatory requirements. Distributions to
shareholders are recorded on the ex-dividend date. Income and capital gain
distributions are determined in accordance with income tax regulations, which
may differ from generally accepted accounting principles. These differences are
primarily due to investments in forward contracts, passive foreign investment
companies, the deferral of wash sale losses, and paydowns on certain
mortgage-backed securities. As a result, net investment income and net realized
gain on investment transactions for a reporting period may differ significantly
from distributions during such period.
Accordingly, the Funds may periodically make reclassifications among certain of
their capital accounts without impacting the net asset value of the Funds.
22
<Page>
During the year ended December 31, 2004, the following amounts were reclassified
due to the differences between book and tax accounting:
<Table>
<Caption>
ACCUMULATED
NET REALIZED UNDISTRIBUTED
PAID-IN GAIN (LOSS) ON NET INVESTMENT
CAPITAL INVESTMENTS INCOME
---------- -------------- --------------
Equity Index Fund $ (48,163) $ 47,226 $ 937
Small Cap Equity Fund 1 (2,385) 2,384
</Table>
FOREIGN CURRENCY TRANSLATION
The books and records of the Funds are maintained in U.S. dollars. The market
values of foreign currencies, foreign securities and other assets and
liabilities denominated in foreign currencies are translated into U.S. dollars
at the mean of the buying and selling rates of such currencies against the U.S.
dollar at the end of each business day. Purchases and sales of foreign
securities and income and expense items are translated at the rates of exchange
prevailing on the respective dates of such transactions. The Funds do not
isolate that portion of the results of operations arising from changes in the
exchange rates from that portion arising from changes in the market prices of
securities.
Net realized foreign currency gains and losses resulting from changes in
exchange rates include foreign currency gains and losses between trade date and
settlement date on investment securities transactions, foreign currency
transactions and the difference between the amounts of dividends recorded on the
books of the Funds and the amount actually received.
FORWARD FOREIGN CURRENCY CONTRACTS
Each Fund may enter into forward foreign currency contracts in order to hedge
the effect of currency movements of foreign denominated securities or
obligations. A forward foreign currency contract is an agreement between two
parties to buy and sell a currency at a set price on a future date. The market
value of a forward foreign currency contract fluctuates with changes in foreign
currency exchange and interest rates. Forward foreign currency contracts are
marked to market daily and the change in their value is recorded by the Funds as
an unrealized gain or loss. When a forward foreign currency contract is
extinguished, through delivery or offset by entering into another forward
foreign currency contract, the Funds record a realized gain or loss equal to the
difference between the value of the contract at the time it was opened and the
value of the contract at the time it was extinguished or offset.
Forward foreign currency contracts involve a risk of loss from the potential
inability of counterparties to meet the terms of their contracts and from
unanticipated movements in foreign currency values and interest rates.
The notional or contractual amounts of these instruments represent the
investments the Funds have in particular classes of financial instruments and do
not necessarily represent the amounts potentially subject to risk. The
measurement of the risk associated with these instruments is meaningful only
when all related and offsetting transactions are considered.
At December 31, 2004, the Funds had no open forward foreign currency contracts.
FORWARD COMMITMENTS
Each Fund may purchase or sell securities on a "when issued" or delayed delivery
or on a forward commitment basis. The Funds use forward commitments to manage
interest rate exposure or as a temporary substitute for purchasing or selling
particular debt securities. Delivery and payment for securities purchased on a
forward commitment basis can take place a month or more after the date of the
transaction. The Funds instruct the custodian to segregate assets in a separate
account with a current market value at least equal to the amount of its forward
purchase commitments. The price of the underlying security and the date when the
securities will be delivered and paid for are fixed at the time the transaction
is negotiated. Forward commitments are valued on the basis of valuations
furnished by a pricing service, authorized by the Trustees, which determines
valuations taking into account appropriate factors such as institutional-size
trading in similar groups of securities, yield, quality, coupon rate, maturity,
23
<Page>
type of issue, trading characteristics and other market data. Securities for
which no market quotation is available, are valued at fair value in accordance
with procedures approved by and determined in good faith by the Trustees,
although the actual calculation may be done by others. The Funds record on a
daily basis the unrealized appreciation (depreciation) based upon changes in the
value of the forward commitment. When a forward commitment contract is closed,
the Funds record a realized gain or loss equal to the difference between the
value of the contract at the time it was opened and the value of the contract at
the time it was extinguished. Forward commitments involve a risk of loss if the
value of the security to be purchased declines prior to the settlement date. The
Funds could also be exposed to loss if they cannot close out their forward
commitments because of an illiquid secondary market, or the inability of
counterparties to perform. The Funds monitor exposure to ensure counterparties
are creditworthy and concentration of exposure is minimized.
At December 31, 2004, the Funds had no open forward commitments.
FINANCIAL FUTURES CONTRACTS
The Funds may purchase or sell financial futures contracts and options on such
futures contracts for the purpose of hedging the market risk on existing
securities or as a substitute for the purchase of securities. Futures contracts
are contracts for delayed delivery of securities at a specific future date and
at a specific price or yield. Upon entering into a contract, the Funds deposit
and maintain as collateral such initial margin as required by the exchange on
which the transaction is effected. Pursuant to the contract, the Fund agrees to
receive from or pay to the broker an amount of cash equal to the daily
fluctuation in value of the contract. Such receipts or payments are known as
variation margin and are recorded by the Funds as unrealized gains or losses.
When the contract is closed, each Fund records a realized gain or loss equal to
the difference between the value of the contract at the time it was opened and
the value at the time it was closed. Futures contracts are valued at the
settlement price established each day by the board of trade or exchange on which
they are traded.
A summary of open futures contracts for the Equity Index Fund at December 31,
2004, is as follows:
<Table>
<Caption>
NOTIONAL NET
NUMBER OF CONTRACT UNREALIZED
CONTRACTS TYPE EXPIRATION DATE VALUE APPRECIATION
- ------------------- ------------- --------------- ------------ ------------
EQUITY INDEX FUND
BUYS
11 S&P 500 Index 03/17/05 $ 3,337,675 $ 78,546
</Table>
ALLOCATION OF OPERATING ACTIVITY
In maintaining the records for the Equity Index Fund, the income and expense
accounts are allocated to each class of shares. Investment income, unrealized
and realized gains or losses are prorated among the classes of shares based on
the relative net assets of each. Expenses are allocated to each class of shares
depending on the nature of the expenditures. Administration fees, which are
directly attributable to a class of shares, are charged to that class'
operations. Expenses of the Fund not directly attributable to the operations of
any class of shares are prorated among the classes to which the expense relates
based on the relative net assets of each.
3. MANAGEMENT FEES AND OTHER TRANSACTIONS
INVESTMENT MANAGEMENT FEES
Under agreements between the Trust and MassMutual on behalf of each Fund,
MassMutual is responsible for providing investment management services for
each Fund. In return for this service, MassMutual receives advisory fees
monthly based on the following annual rates.
For the Equity Index Fund, MassMutual receives a fee from the Fund at an
annual rate of 0.10% of the average daily net asset value of the Fund.
24
<Page>
For the Small Cap Equity Fund, MassMutual receives a fee from the Fund at an
annual rate of 0.65% of the first $100,000,000, 0.60% of the next $100,000,000,
0.55% of the next $300,000,000 and 0.50% of any excess over $500,000,000 of the
average daily net asset value of the Fund.
MassMutual has entered into an investment sub-advisory agreement with Babson
Capital Management LLC ("Babson Capital"), (formerly known as David L. Babson &
Company Inc.) pursuant to which Babson Capital serves as the Small Cap Equity
Fund's sub-adviser providing day-to-day management of the Fund's investments.
Babson Capital is a wholly-owned subsidiary of DLB Acquisition Corporation,
which is a controlled subsidiary of MassMutual. Babson Capital receives a fee
from MassMutual equal to an annual rate of 0.25% of the average daily net assets
under management of the Fund.
MassMutual has also entered into an investment sub-advisory agreement with
Northern Trust Investments, N.A. ("Northern Trust") for the Equity Index Fund.
MassMutual pays a sub-advisory fee to Northern Trust based upon the aggregate
net assets under management which include (1) the average daily net assets of
the Equity Index Fund, and (2) the average daily net assets of all other funds
or accounts of MassMutual or its affiliates for which Northern Trust provides
sub-advisory services and which have substantially the same investment
objectives, policies and investment strategies.
ADMINISTRATION & SHAREHOLDER SERVICE FEES
For the Equity Index Fund, under a separate administrative and shareholder
services agreement between the Fund and MassMutual, MassMutual provides certain
administrative and shareholder services and bears some class specific
administrative expenses. In return for these services, MassMutual receives an
administrative services fee monthly based upon the average daily net assets of
the applicable class of shares of the Fund at the following annual rates: 0.30%
on the first $100,000,000, 0.28% on the next $150,000,000 and 0.26% on assets in
excess of $250,000,000 of Class I shares of the Fund, 0.19% of the average daily
net assets of Class II shares of the Fund, and for Class III shares, an amount
not to exceed 0.05% of the average daily net assets of the Fund.
EXPENSE WAIVERS
For the Small Cap Equity Fund, MassMutual has agreed, at least through April 30,
2005, to bear the expenses of the Fund to the extent that the aggregate expenses
(excluding the Fund's management fee, interest, taxes, brokerage commissions and
extraordinary expenses) incurred during the Fund's fiscal year exceed 0.11% of
the average daily net assets of the Fund for such year.
For Class II and Class III of the Equity Index Fund, MassMutual has agreed, at
least through April 30, 2005, to bear the expenses of the Fund, to the extent
that the aggregate expenses (excluding the Fund's management and administrative
fees, interest, taxes, brokerage commissions and extraordinary expenses)
incurred during the Fund's fiscal year exceed 0.05% of the average daily net
assets of the Fund for such year. MassMutual has also agreed to waive certain
administrative and shareholder service fees payable by the Fund on account of
Class II or Class III shares.
EXPENSE REDUCTIONS
The Small Cap Equity Fund has entered into an agreement with certain brokers
whereby the brokers will rebate, in cash, a portion of brokerage commissions and
such cash will be applied to reduce fund expenses. The amount earned by the Fund
under such an agreement is presented as a reduction of the expenses in the
statement of operations. For the year ended December 31, 2004, there was no
expense reduction under this agreement.
OTHER
Certain officers and trustees of the Funds are also officers of MassMutual. The
compensation of each trustee who is not an officer or employee of MassMutual is
borne by the Funds.
DEFERRED COMPENSATION
Trustees of the Funds that are not employees of MassMutual or its subsidiaries
may elect to defer receipt of their annual fees in accordance with terms of the
Non-Qualified Deferred Compensation Plan. Any amounts deferred shall accrue
interest at a rate equal to eight percent (8%) per annum.
For the year ended December 31, 2004, no significant amounts have been deferred.
25
<Page>
4. PURCHASES AND SALES OF INVESTMENTS
Cost of purchases and proceeds from sales of investment securities (excluding
short-term investments) for the year ended December 31, 2004, were as follows:
<Table>
<Caption>
LONG-TERM U.S. OTHER LONG-TERM
GOVERNMENT SECURITIES SECURITIES
--------------------- ---------------
PURCHASES
Equity Index Fund $ - $ 15,643,905
Small Cap Equity Fund - 36,726,714
SALES
Equity Index Fund $ - $ 45,944,963
Small Cap Equity Fund - 32,652,163
</Table>
5. CAPITAL SHARE TRANSACTIONS
The Funds are authorized to issue an unlimited number of shares, with no par
value in each class of shares. Changes in shares outstanding for each Fund are
as follows:
<Table>
<Caption>
YEAR ENDED DECEMBER 31, 2004 YEAR ENDED DECEMBER 31, 2003
SHARES AMOUNT SHARES AMOUNT
---------- --------------- ---------- ---------------
EQUITY INDEX FUND CLASS I
Sold 1,190,416 $ 16,724,615 1,373,601 $ 16,523,967
Issued as reinvestment of dividends 90,073 1,343,884 66,793 913,733
Redeemed (1,299,529) (18,067,066) (1,104,652) (12,742,287)
---------- --------------- ---------- ---------------
Net increase (decrease) (19,040) $ 1,433 335,742 $ 4,695,413
========== =============== ========== ===============
EQUITY INDEX FUND CLASS II
Sold 1,537,829 $ 21,537,619 3,785,872 $ 45,312,735
Issued as reinvestment of dividends 213,984 3,190,498 181,866 2,486,104
Redeemed (3,163,722) (44,605,532) (1,822,195) (20,970,465)
---------- --------------- ---------- ---------------
Net increase (decrease) (1,411,909) $ (19,877,415) 2,145,543 $ 26,828,374
========== =============== ========== ===============
EQUITY INDEX FUND CLASS III
Sold 19,216 $ 267,033 766,101 $ 8,254,570
Issued as reinvestment of dividends 171,337 2,549,488 141,618 1,931,671
Redeemed (1,043,953) (14,627,174) (1,499,750) (17,541,572)
---------- --------------- ---------- ---------------
Net increase (decrease) (853,400) $ (11,810,653) (592,031) $ (7,355,331)
========== =============== ========== ===============
SMALL CAP EQUITY FUND
Sold 1,158,338 $ 13,270,784 1,543,870 $ 14,782,305
Issued as reinvestment of dividends 154,079 1,963,832 12,718 142,999
Redeemed (1,084,794) (12,425,250) (1,081,987) (10,032,551)
---------- --------------- ---------- ---------------
Net increase (decrease) 227,623 $ 2,809,366 474,601 $ 4,892,753
========== =============== ========== ===============
</Table>
6. FOREIGN SECURITIES
The Funds may also invest in foreign securities, subject to certain percentage
restrictions. Investing in securities of foreign companies and foreign
governments involves special risks and considerations not typically associated
with investing in securities issued by U.S. companies and the U.S. Government.
These risks include revaluation of currencies and future adverse political and
economic developments. Moreover, securities of many foreign companies and
foreign governments and their markets may be less liquid and their prices more
volatile than those of securities of comparable U.S. companies and the U.S.
Government.
26
<Page>
7. FEDERAL INCOME TAX INFORMATION
At December 31, 2004, the cost of securities and the unrealized appreciation
(depreciation) in the value of investments owned by the Funds, as computed on a
Federal income tax basis, were as follows:
<Table>
<Caption>
FEDERAL TAX BASIS TAX BASIS NET UNREALIZED
INCOME TAX UNREALIZED UNREALIZED APPRECIATION/
COST APPRECIATION DEPRECIATION (DEPRECIATION)
------------- ------------ ------------- --------------
Equity Index Fund $ 408,584,626 $ 67,282,198 $ (42,397,641) $ 24,884,557
Small Cap Equity Fund 86,990,030 28,219,593 (1,528,322) 26,691,271
</Table>
At December 31, 2004, the following Funds had available, for Federal income tax
purposes, unused capital losses:
<Table>
<Caption>
EXPIRING EXPIRING EXPIRING
2010 2011 2012
------------ ------------- --------------
Equity Index Fund $ 6,501,477 $ 110,945 $ 2,367,627
</Table>
Net capital loss carryforwards may be applied against any net realized taxable
gains in each succeeding year, or until their respective expiration dates,
whichever occurs first.
Certain differences exist from the amounts reflected in the Statement of Changes
in Net Assets primarily due to the character of short-term capital gains treated
as ordinary income for tax purposes. The tax character of distributions paid
during the year ended December 31, 2004 was as follows:
<Table>
<Caption>
ORDINARY LONG TERM RETURN OF
INCOME CAPITAL GAIN CAPITAL
------------ ------------- --------------
Equity Index Fund $ 7,083,870 $ - $ -
Small Cap Equity Fund 516,795 1,447,037 -
</Table>
The tax character of distributions paid during the year ended December 31, 2003
was as follows:
<Table>
<Caption>
ORDINARY LONG TERM RETURN OF
INCOME CAPITAL GAIN CAPITAL
------------ ------------ --------------
Equity Index Fund $ 5,331,508 $ - $ -
Small Cap Equity Fund 142,999 - -
</Table>
At December 31, 2004, the components of distributable earnings on a tax basis
were as follows:
<Table>
<Caption>
UNDISTRIBUTED OTHER
ORDINARY CAPITAL LOSS TEMPORARY UNREALIZED
INCOME CARRYOVER DIFFERENCES APPRECIATION*
------------- ------------ ------------- -------------
Equity Index Fund $ - $ (8,980,049) $ (1,207,997) $ 24,963,103
Small Cap Equity Fund 358,180 - (128,332) 26,691,271
</Table>
* INCLUDES UNREALIZED APPRECIATION (DEPRECIATION) ON INVESTMENTS, DERIVATIVES
AND FOREIGN CURRENCY DENOMINATED ASSETS AND LIABILITIES IF ANY.
The following Funds elected to defer to January 1, 2005 post-October losses:
<Table>
<Caption>
AMOUNT
-------------
Equity Index Fund $ 1,178,443
Small Cap Equity Fund 120,428
</Table>
27
<Page>
8. PROXY VOTING (UNAUDITED)
A description of the policies and procedures that each Fund's investment adviser
and sub-advisers use to vote proxies relating to the Fund's portfolio securities
is available, without charge, upon request, by calling 1-888-309-3539, and on
the Securities and Exchange Commission's website at http://www.sec.gov.
Information regarding how the Funds voted proxies relating to portfolio
securities during the most recent 12-month period ended June 30 is available,
without charge, upon request, on the MassMutual website at
http://www.massmutual.com/retire and on the Securities and Exchange Commission's
website at http://www.sec.gov.
9. QUARTERLY REPORTING (UNAUDITED)
The Funds file their complete schedule of portfolio holdings with the SEC for
the first and third quarters of each fiscal year on Form N-Q. The Funds' Forms
N-Q are available on the SEC website at http://www.sec.gov. The Funds' Forms N-Q
may be reviewed and copied at the SEC's Public Reference Room, which may be
obtained by calling 1-800-SEC-0330.
28
<Page>
REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM
TO THE BOARD OF TRUSTEES AND SHAREHOLDERS OF MML SERIES INVESTMENT FUND
We have audited the accompanying statement of assets and liabilities, including
the portfolios of investments, of the MML Equity Index Fund and the MML Small
Cap Equity Fund (collectively the "Funds") which are components of the MML
Series Investment Fund ("The MML Trust"), as of December 31, 2004, and the
related statements of operations for the year then ended, the statements of
changes in net assets for each of the two years in the period then ended, and
the financial highlights for each of the five years in the period then ended.
These financial statements and financial highlights are the responsibility of
the MML Trust's management. Our responsibility is to express an opinion on these
financial statements and financial highlights based on our audits.
We conducted our audits in accordance with the standards of the Public Company
Accounting Oversight Board (United States). Those standards require that we plan
and perform the audit to obtain reasonable assurance about whether the financial
statements are free of material misstatement. An audit includes consideration of
internal control over financial reporting as a basis for designing audit
procedures that are appropriate in the circumstances, but not for the purpose of
expressing an opinion of the effectiveness of the Funds' internal control over
financial reporting. Accordingly, we express no such opinion. An audit also
includes examining, on a test basis, evidence supporting the amounts and
disclosures in the financial statements, assessing the accounting principles
used and significant estimates made by management, as well as evaluating the
overall financial statement presentation. Our procedures included confirmation
of securities owned as of December 31, 2004 by correspondence with the custodian
and brokers; where replies were not received from brokers, we performed other
auditing procedures. We believe that our audits provide a reasonable basis for
our opinion.
In our opinion, such financial statements and financial highlights referred to
above present fairly, in all material respects, the financial position of the
Funds as of December 31, 2004, and the results of their operations, the changes
in their net assets for each of the two years in the period then ended and their
financial highlights for each of the five years in the period then ended in
conformity with accounting principles generally accepted in the United States of
America.
/s/ Deloitte & Touche LLP
Deloitte & Touche LLP
Boston, Massachusetts
February 11, 2005
29
<Page>
TRUSTEES AND OFFICERS (UNAUDITED)
The following table lists the Trust's trustees and officers as of December 31,
2004; their address and age; their position with the Trust; the length of time
holding that position with the Trust; their principal occupation(s) during the
past five years; the number of portfolios in the fund complex they oversee; and
other directorships they hold in companies subject to registration or reporting
requirements of the Securities Exchange Act of 1934 (generally called "public
companies") or in registered investment companies. The Trust's Statement of
Additional Information includes additional information about the Trust's
trustees and is available, without charge, upon request by calling
1-888-309-3539 or by writing MML Series Investment Fund, c/o Massachusetts
Mutual Life Insurance Company, 1295 State Street, Springfield, Massachusetts
01111-0111, Attention: Retirement Services Marketing.
DISINTERESTED TRUSTEES
<Table>
<Caption>
TERM NUMBER OF
OF OFFICE** PORTFOLIOS IN
AND FUND
POSITION(S) LENGTH PRINCIPAL COMPLEX OTHER
NAME, ADDRESS*, HELD WITH OF TIME OCCUPATION(S) DURING OVERSEEN BY DIRECTORSHIPS
AND AGE TRUST SERVED PAST 5 YEARS TRUSTEE HELD BY TRUSTEE
- ------------------------ ----------- ----------- -------------------------------- ------------- -------------------------------
Richard H. Ayers Trustee of Since 1999 Retired. 39 Director, Applera Corporation;
Age: 62 the Trust Director (since 2002), Instron
Corporation.
Mary E. Boland Trustee of Since 1973 Attorney at Law (since 2004); 39 Director (since 1999),
Age: 65 the Trust Attorney at Law (1965-2004), BankNorth Massachusetts;
Egan, Flanagan and Cohen, P.C. Director (since 1999),
(law firm), Springfield, MA. Massachusetts Educational
Financing Authority.
Richard W. Greene Trustee of Since 1999 Retired; Vice President for 39
Age: 69 the Trust Investments and Treasurer
(1998-2000), University of
Rochester (private university).
F. William Marshall, Jr. Trustee of Since 1996 Consultant (since 1999); 39 Trustee (since 2000), Board II
Age: 62 the Trust Chairman (1999), Family Bank, Oppenheimer Funds.
F.S.B. (formerly SIS Bank);
Executive Vice President (1999),
Peoples Heritage Financial
Group; President, Chief
Executive Officer and Director
(1993-1999), SIS Bancorp, Inc.
and SIS Bank (formerly,
Springfield Institution for
Savings).
Allan W. Blair Trustee of Since 2003 President and Chief Executive 39 Director (since 2001), Future
Age: 56 the Trust Officer (since 1996), Economic Works, Inc.
Development Council of Western
Massachusetts; President and
Chief Operating Officer (since
1993), Westmass Area Development
Corporation; President and Chief
Operating Officer (since 1984),
Westover Metropolitan
Development Corporation.
R. Alan Hunter, Jr. Trustee of Since 2003 Retired. 39
Age: 58 the Trust
</Table>
30
<Page>
INTERESTED TRUSTEES
<Table>
<Caption>
TERM NUMBER OF
OF OFFICE** PORTFOLIOS IN
AND FUND
POSITION(S) LENGTH PRINCIPAL COMPLEX OTHER
NAME, ADDRESS*, HELD WITH OF TIME OCCUPATION(S) DURING OVERSEEN BY DIRECTORSHIPS
AND AGE TRUST SERVED PAST 5 YEARS TRUSTEE HELD BY TRUSTEE
- ------------------------ ----------- ----------- -------------------------------- ------------- -------------------------------
Stuart H. Reese Chairman Since 1999 Executive Vice President and 41 Chairman (since 1999),
Age: 49 and Chief Investment Officer (since President (1995-1999),
Trustee of 1999), Chief Executive Director MassMutual Corporate Investors
the Trust (1997-1999), MassMutual; and MassMutual Participation
Chairman and Chief Executive Investors (closed-end
Officer (since 2001), President investment companies);
and Chief Executive Officer Director (since 1999), Merrill
(1999-2001), Babson Capital Lynch Derivative Products;
Management LLC (investment Chairman (since 1999),
adviser). Director (since 1996), Antares
Capital Corporation (finance
company); Director (since
1996), HYP Management, Inc.
(managing member of MassMutual
High Yield Partners LLC), and
MMHC Investment, Inc.
(investor in funds sponsored
by MassMutual); Director
(since 1994), MassMutual
Corporate Value Partners
Limited (investor in debt and
equity securities) and
MassMutual Corporate Value
Limited (parent of MassMutual
Corporate Value Partners
Limited); President (since
1997), MassMutual/ Darby CBO
IM Inc. (manager of
MassMutual/ Darby CBO LLC, a
high yield bond fund);
Advisory Board Member (since
1995), Kirtland Capital
Partners.
Frederick C. Castellani Trustee of Since 2001 Executive Vice President (since 39
Age: 58 the Trust 2001), Senior Vice President
(1996-2001), MassMutual.
Robert E. Joyal Trustee of Since 2003 Retired; President (2001-2003), 41 Trustee (since 2003),
Age: 59 the Trust Managing Director (2000-2001) President (1999-2003),
and Executive Director MassMutual Corporate Investors
(1999-2000), David L. Babson & and MassMutual Participation
Company Inc.; Executive Director Investors (closed-end
(1997-1999), Massachusetts investment companies);
Mutual Life Insurance Company. Director (since 1996), Antares
Capital Corporation (bank loan
syndication); Director (since
1996), First Israel Mezzanine
Investors Ltd. (general
partner and manager of The
Israel Mezzanine Fund, L.P.);
Director (since 2003), Pemco
Aviation Group, Inc.
</Table>
31
<Page>
PRINCIPAL OFFICERS WHO ARE NOT TRUSTEES
<Table>
<Caption>
NUMBER OF
PORTFOLIOS IN
FUND
POSITION(S) LENGTH PRINCIPAL COMPLEX
NAME, ADDRESS*, HELD WITH OF TIME OCCUPATION(S) DURING OVERSEEN BY
AND AGE TRUST SERVED PAST 5 YEARS OFFICER
- ------------------ ---------------- ------- ----------------------------------------------------- -------------
David W. O'Leary President of the Since Senior Vice President (since 2001), MassMutual; 14
Age: 44 Trust 2004 Senior Vice President (1999-2001), Vice President
(1996-1999), Aetna Financial Services.
James S. Collins Chief Financial Since Vice President (since 1999), Second Vice President 39
Age: 46 Officer and 2000 (1990-1999), MassMutual.
Treasurer of
Trust
Thomas M. Kinzler Vice President Since Vice President and Associate General Counsel (since 59
Age: 49 and Secretary 1999 1999), Second Vice President and Associate General
of the Trust Counsel (1996-1999), MassMutual.
Toby Slodden Vice President Since Executive Vice President (since 2003), Senior Vice 39
Age: 47 of the Trust 2003 President (1999-2003), Vice President (1997-1999),
MassMutual.
Michael A. Chong Vice President Since Vice President, Compliance (since 2004), Vice 59
Age: 47 and Chief 2004 President and Associate General Counsel (1999-2004),
Compliance Second Vice President (1996-1999), MassMutual.
Officer of the
Trust
Ian W. Sheridan Vice President Since Vice President (since 2003), MassMutual; Vice 39
Age: 39 of the Trust 2004 President of Marketing and Business Development
(1999-2003), Automatic Data Processing (ADP).
</Table>
* The address of each Trustee and Principal Officer is the same as that for
the Trust; 1295 State Street, Springfield, Massachusetts 01111.
** Each Trustee of the Trust serves until the next meeting of shareholders
called for the purpose of electing Trustees and until the election and
qualification of his successor or until he dies, resigns or is removed.
Notwithstanding the foregoing, a Trustee shall retire and cease to serve as
a Trustee as of the first board meeting following the date on which the
Trustee attains the age of seventy-two years.
FEDERAL TAX INFORMATION (UNAUDITED)
For corporate shareholders, a portion of the ordinary dividends paid during the
Fund's year ended December 31, 2004 qualified for the dividends received
deduction, as follows:
<Table>
Equity Index Fund 100.00%
Small Cap Equity Fund 100.00%
</Table>
32
<Page>
FUND EXPENSES DECEMBER 31, 2004
EXPENSE EXAMPLES
The following information is in regards to expenses for the six month period
ended December 31, 2004:
As a shareholder of the Funds, you incur ongoing costs, including management
fees and other Fund expenses. These examples are intended to help you understand
your ongoing costs (in dollars) of investing in the Funds and to compare these
costs with the ongoing costs of investing in other mutual funds.
These examples are based on an investment of $1,000 invested for the six month
period ended December 31, 2004.
ACTUAL EXPENSES
The first line of each table on the following pages provides information about
actual account values and actual expenses. You may use the information in this
line, together with the amount you invested, to estimate the expenses that you
paid over the period. Simply divide your account value by $1,000 (for example,
an $8,600 account value divided by $1,000 = 8.6), then multiply the result by
the number in the first line under the heading entitled "Operating Expenses
Incurred" to estimate the expenses you paid on your account during this period.
HYPOTHETICAL EXAMPLE FOR COMPARISON PURPOSES
The second line of each table on the following pages provides information about
hypothetical account values and hypothetical expenses based on the Fund's actual
expense ratio and an assumed rate of return of 5% per year before expenses,
which is not the Fund's actual return. The hypothetical account values and
expenses may not be used to estimate the actual ending account balance or
expenses you paid for the period. You may use this information to compare the
ongoing costs of investing in the Fund and other funds. To do so, compare this
5% hypothetical example with the 5% hypothetical examples that appear in the
shareholder reports of the other funds.
Please note that the expenses shown in the tables are meant to highlight your
ongoing costs only. Therefore, the second line of the table is useful in
comparing ongoing costs only, and will not help you determine the relative total
costs of owning different funds.
33
<Page>
The Funds incur ongoing operating expenses during the normal course of business,
such as management fees and other expenses. The following tables, assuming a
$1,000 investment in a class of shares, disclose the ending account value and
operating expenses incurred for the six months ended December 31, 2004, based
on, (1) the Fund's actual return and actual expenses, and (2) a hypothetical
annualized 5% return and the Fund's actual expenses:
EQUITY INDEX FUND
CLASS I
<Table>
<Caption>
OPERATING
BEGINNING ENDING EXPENSE
VALUE VALUE INCURRED*
----------- ---------- ---------
1) Actual $ 1,000.00 $ 1,069.10 $ 2.34
2) Hypothetical 1,000.00 1,022.87 2.29
</Table>
- ----------
* EXPENSES ARE CALCULATED USING THE ANNUALIZED EXPENSE RATIO FOR THE SIX MONTHS
ENDED DECEMBER 31, 2004 OF 0.45%, MULTIPLIED BY THE AVERAGE ACCOUNT VALUE
OVER THE PERIOD, MULTIPLIED BY THE NUMBER OF DAYS IN THE PERIOD, DIVIDED BY
THE NUMBER OF DAYS IN THE YEAR.
CLASS II
<Table>
<Caption>
OPERATING
BEGINNING ENDING EXPENSE
VALUE VALUE INCURRED*
----------- ---------- ---------
1) Actual $ 1,000.00 $ 1,070.10 $ 1.51
2) Hypothetical 1,000.00 1,023.68 1.48
</Table>
- ----------
* EXPENSES ARE CALCULATED USING THE ANNUALIZED EXPENSE RATIO FOR THE SIX MONTHS
ENDED DECEMBER 31, 2004 OF 0.29%, MULTIPLIED BY THE AVERAGE ACCOUNT VALUE
OVER THE PERIOD, MULTIPLIED BY THE NUMBER OF DAYS IN THE PERIOD, DIVIDED BY
THE NUMBER OF DAYS IN THE YEAR.
CLASS III
<Table>
<Caption>
OPERATING
BEGINNING ENDING EXPENSE
VALUE VALUE INCURRED*
----------- ---------- ---------
1) Actual $ 1,000.00 $ 1,070.80 $ 0.78
2) Hypothetical 1,000.00 1,024.38 0.76
</Table>
- ----------
* EXPENSES ARE CALCULATED USING THE ANNUALIZED EXPENSE RATIO FOR THE SIX MONTHS
ENDED DECEMBER 31, 2004 OF 0.15%, MULTIPLIED BY THE AVERAGE ACCOUNT VALUE
OVER THE PERIOD, MULTIPLIED BY THE NUMBER OF DAYS IN THE PERIOD, DIVIDED BY
THE NUMBER OF DAYS IN THE YEAR.
SMALL CAP EQUITY FUND
<Table>
<Caption>
OPERATING
BEGINNING ENDING EXPENSE
VALUE VALUE INCURRED*
----------- ---------- ---------
1) Actual $ 1,000.00 $ 1,109.90 $ 3.71
2) Hypothetical 1,000.00 1,021.62 3.56
</Table>
* EXPENSES ARE CALCULATED USING THE ANNUALIZED EXPENSE RATIO FOR THE SIX MONTHS
ENDED DECEMBER 31, 2004 OF 0.70%, MULTIPLIED BY THE AVERAGE ACCOUNT VALUE
OVER THE PERIOD, MULTIPLIED BY THE NUMBER OF DAYS IN THE PERIOD, DIVIDED BY
THE NUMBER OF DAYS IN THE YEAR.
34
<Page>
[MASSMUTUAL FINANCIAL GROUP(SM) LOGO]
Massachusetts Mutual Life Insurance Company and affiliates, Springfield, MA
01111-0001
www.massmutual.com
MassMutual Financial Group is a marketing designation (or fleet name) for
Massachusetts Mutual Life Insurance Company (MassMutual) and its affiliates.
L4540-2 205
<Page>
ITEM 2 CODE OF ETHICS.
As of December 31, 2004, the Registrant adopted a Code of Ethics that
applies to the Principal Executive Officer and Principal Financial Officer
pursuant to the Sarbanes-Oxley Act of 2002. For the year ended December 31,
2004, there were no amendments to a provision of the Code of Ethics. A copy of
its Code of Ethics is filed with this Form N-CSR under item 10 (a).
ITEM 3 AUDIT COMMITTEE FINANCIAL EXPERT.
The Registrant's Board of Trustees has determined that Richard H.
Ayers and Richard W. Greene, both members of the Audit Committee, are audit
committee financial experts as defined by the Securities and Exchange Commission
(the "SEC"). Mr. Ayers and Mr. Greene are "independent" as defined by the SEC
for purposes of audit committee financial expert determinations.
ITEM 4 PRINCIPAL ACCOUNTANT FEES AND SERVICES.
(a) AUDIT FEES: The aggregate fees paid and accrued by the Registrant
for professional services rendered by its independent auditors,
Deloitte & Touche LLP, for the audit of the Registrant's annual
financial statements for 2004 and 2003 were $38,100 and $35,968,
respectively.
(b) AUDIT RELATED FEES: No such fees were billed to the Registrant by
Deloitte & Touche LLP for 2004 and 2003.
(c) TAX FEES: The aggregate fees paid or accrued by the Registrant
for professional services rendered by Deloitte & Touche LLP for
the review of Form 1120-RIC, Form 8613, excise distribution
projections, distribution calculation and reasonable out of
pocket expenses for 2004 and 2003 were $5,414 and $6,057,
respectively.
(d) ALL OTHER FEES: No such fees were billed to the Registrant by
Deloitte & Touche LLP for 2004 or 2003.
(e) (1) AUDIT COMMITTEE PRE-APPROVAL POLICY: All services to be
performed for the Registrant by Deloitte & Touche LLP must be
pre-approved by the audit committee. All services performed
during 2004 and 2003 were pre-approved by the committee.
(2) Not applicable.
(f) Not applicable.
(g) Not applicable.
(h) Not applicable.
ITEM 5 AUDIT COMMITTEE OF LISTED REGISTRANTS.
Not applicable to this filing.
ITEM 6 SCHEDULE OF INVESTMENTS
Not applicable to this filing.
ITEM 7 DISCLOSURE OF PROXY VOTING POLICIES AND PROCEDURES FOR CLOSED-END
MANAGEMENT INVESTMENT COMPANIES.
Not applicable to this filing.
<Page>
ITEM 8 PURCHASE OF EQUITY SECURITIES BY CLOSED-END MANAGEMENT INVESTMENT COMPANY
AND AFFILIATED PURCHASERS.
Not applicable to this filing.
ITEM 9 SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS.
Not applicable to this filing.
ITEM 10 CONTROLS AND PROCEDURES.
(a) The Registrant's Principal Executive Officer and Principal
Financial Officer concluded that the Registrant's disclosure controls
and procedures (as defined in Rule 30a-3(c) under the Investment
Company Act of 1940) were effective based as of a date within 90 days
prior to the filing date of this report (the "Evaluation Date"), based
on their evaluation of the effectiveness of the Registrant's
disclosure controls and procedures as of the Evaluation Date.
(b) There were no changes in the Registrant's internal control over
financial reporting (as defined in Rule 30a-3(d) under the 1940 Act
(17 CFR 270.30a-3(d)) that occurred during the Registrant's last
fiscal half-year (the Registrant's second fiscal half-year in the case
of an annual report) that has materially affected, or is reasonably
likely to materially affect, the Registrant's internal control over
financial reporting.
ITEM 11 (EXHIBITS):
(a)(1) Code of Ethics Described in Item 2 is attached.
(a)(2) Certifications of the Principal Executive Officer and Principal
Financial Officer of the Registrant as required by Rule 30a-2(a) under
the Investment Company Act of 1940 (17 CFR 270.30a-2(a) are attached
hereto as Exhibit 99CERT.
(a)(3) Any written solicitation to purchase securities under Rule
23c-1 under the Act (17 CFR 270.23c-1) sent or given during the period
covered by the report by or on behalf of the registrant to 10 or more
persons.
(b) Certifications pursuant to Section 906 of the Sarbanes-Oxley Act
of 2002 as required by Rule 30a-2(b), under the Investment Company Act
of 1940 (17 CFR 270.30a-2(b)), Rule 15d-14(b) under the Securities
Exchange Act of 1934 (17 CFR 240.15d-14(b)) and Section 1350 of
Chapter 63 of Title 18 of the United States Code (18 U.S.C. 1350) is
attached hereto as Exhibit 99.906CERT.
SIGNATURES
Pursuant to the requirements of the Securities Exchange Act of 1934 and the
Investment Company Act of 1940, the Registrant has duly caused this report to be
signed on its behalf by the undersigned, thereunto duly authorized.
(Registrant) MML Series Investment Fund
By (Signature and Title): /s/ David W. O'Leary
--------------------------------------------
David W. O'Leary, President and Principal Executive
Officer
Date 2/24/05
----------
<Page>
Pursuant to the requirements of the Securities Exchange Act of 1934 and the
Investment Company Act of 1940, this report has been signed below by the
following persons on behalf of the Registrant and in the capacities, and on the
dates indicated.
By (Signature and Title): /s/ David W. O'Leary
--------------------------------------------
David W. O'Leary, President and Principal Executive
Officer
Date 2/24/05
----------
By (Signature and Title): /s/ James S. Collins
---------------------------------------------------
James S. Collins, Treasurer and Principal Financial
Officer
Date 3/1/05
----------