0000887147 2024-12-31 2024-12-31 0000887147 cik0000887147:S000002102Member 2024-12-31 2024-12-31 0000887147 cik0000887147:S000002102Member cik0000887147:C000005470Member 2024-12-31 2024-12-31 0000887147 cik0000887147:S000002102Member cik0000887147:C000159676Member 2024-12-31 2024-12-31 0000887147 cik0000887147:S000002102Member cik0000887147:C000005471Member 2024-12-31 2024-12-31 0000887147 cik0000887147:S000002102Member cik0000887147:C000005472Member 2024-12-31 2024-12-31 0000887147 cik0000887147:S000002102Member cik0000887147:C000219320Member 2024-12-31 2024-12-31 0000887147 cik0000887147:S000002102Member rr:RiskLoseMoneyMember 2024-12-31 2024-12-31 0000887147 cik0000887147:S000002102Member cik0000887147:Mid-capstocksMember 2024-12-31 2024-12-31 0000887147 cik0000887147:S000002102Member cik0000887147:GrowthinvestingMember 2024-12-31 2024-12-31 0000887147 cik0000887147:S000002102Member cik0000887147:StockinvestingMember 2024-12-31 2024-12-31 0000887147 cik0000887147:S000002102Member cik0000887147:MarketconditionsMember 2024-12-31 2024-12-31 0000887147 cik0000887147:S000002102Member cik0000887147:SectorexposureMember 2024-12-31 2024-12-31 0000887147 cik0000887147:S000002102Member cik0000887147:PrivateplacementsandIPOsMember 2024-12-31 2024-12-31 0000887147 cik0000887147:S000002102Member cik0000887147:LiquidityMember 2024-12-31 2024-12-31 0000887147 cik0000887147:S000002102Member cik0000887147:ActivemanagementMember 2024-12-31 2024-12-31 0000887147 cik0000887147:S000002102Member cik0000887147:CybersecuritybreachesMember 2024-12-31 2024-12-31 0000887147 cik0000887147:S000002102Member rr:AfterTaxesOnDistributionsMember cik0000887147:C000005470Member 2024-12-31 2024-12-31 0000887147 cik0000887147:S000002102Member rr:AfterTaxesOnDistributionsAndSalesMember cik0000887147:C000005470Member 2024-12-31 2024-12-31 0000887147 cik0000887147:S000002102Member cik0000887147:Russell3000IndexMember 2024-12-31 2024-12-31 0000887147 cik0000887147:S000002102Member cik0000887147:Russell3000Index1Member 2024-12-31 2024-12-31 0000887147 cik0000887147:S000002102Member cik0000887147:Russell3000Index2Member 2024-12-31 2024-12-31 0000887147 cik0000887147:S000002102Member cik0000887147:Russell3000Index3Member 2024-12-31 2024-12-31 0000887147 cik0000887147:S000002102Member cik0000887147:RussellMidcapGrowthIndexMember 2024-12-31 2024-12-31 0000887147 cik0000887147:S000002102Member cik0000887147:RussellMidcapGrowthIndex4Member 2024-12-31 2024-12-31 0000887147 cik0000887147:S000002102Member cik0000887147:RussellMidcapGrowthIndex5Member 2024-12-31 2024-12-31 0000887147 cik0000887147:S000002102Member cik0000887147:LipperMid-CapGrowthFundsIndex6Member 2024-12-31 2024-12-31 0000887147 cik0000887147:S000002102Member cik0000887147:LipperMid-CapGrowthFundsIndex7Member 2024-12-31 2024-12-31 0000887147 cik0000887147:S000002102Member cik0000887147:LipperMid-CapGrowthFundsIndex8Member 2024-12-31 2024-12-31 iso4217:USD pure utr:Y T. Rowe Price Mid-Cap Growth Fund, Inc. 2025-03-01 Mid-Cap Growth Fund Investment Objective(s) The fund seeks to provide long-term capital appreciation by investing in mid-cap stocks with potential for above-average earnings growth. Fees and Expenses This table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the fund. You may also incur brokerage commissions and other charges when buying or selling shares of the fund, which are not reflected in the table or example below. Shareholder fees (fees paid directly from your investment) 20 0 0 0 0 Annual fund operating expenses (expenses that you pay each year as a percentage of the value of your investment) 0.0061 0.0061 0.0061 0.0061 0.0061 0 0 0.0025 0.0050 0 0.0014 0.0002 0.0015 0.0018 0 0.0075 0.0063 0.0101 0.0129 0.0061 0 0 0 0 -0.0061 0.0075 0.0063 0.0101 0.0129 0.0000 Example This example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the fund for the time periods indicated and then redeem all of your shares at the end of those periods, that your investment has a 5% return each year, and that the fund’s operating expenses remain the same. The example also assumes that any current expense limitation arrangement remains in place for the period noted in the previous table; therefore, the figures have been adjusted to reflect fee waivers or expense reimbursements only in the periods for which the expense limitation arrangement is expected to continue. Although your actual costs may be higher or lower, based on these assumptions your costs would be: 77 240 417 930 64 202 351 786 103 322 558 1236 131 409 708 1556 0 0 0 0 Portfolio Turnover The fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when the fund’s shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. During the most recent fiscal year, the fund’s portfolio turnover rate was 22.6% of the average value of its portfolio. Portfolio Turnover 0.226 Principal Investment Strategies The fund normally invests at least 80% of its net assets (plus any borrowings for investment purposes) in a diversified portfolio of common stocks of mid-cap companies whose earnings T. Rowe Price expects to grow at a faster rate than the average company. Any derivatives that provide exposure to the investment focus suggested by the fund’s name, or to one or more market risk factors associated with the investment focus suggested by the fund’s name, are counted (as applicable) toward compliance with the fund’s 80% investment policy. The fund defines mid-cap companies as those whose market capitalization (number of shares outstanding multiplied by share price) falls within the range of either the S&P MidCap 400® Index or the Russell Midcap® Growth Index. As of December 31, 2024, the market capitalization ranges for the S&P MidCap 400® Index and the Russell Midcap® Growth Index were approximately $2.34 billion to $23.01 billion, and $0.93 billion to $164.92 billion, respectively. The market capitalization of the companies in the indexes change over time and the indexes are periodically reconstituted to ensure that they continue to accurately reflect the mid-cap equity market. The fund’s growth-oriented approach to stock selection reflects the belief that when a company’s earnings grow faster than both inflation and the overall economy, it will result in a higher stock price.In selecting investments, the adviser generally favors companies with one or more of the following:· proven products or services;· a record of above-average earnings growth;· demonstrated potential to sustain earnings growth;· connection to an industry experiencing increasing demand; or· stock prices that appear to undervalue their growth prospects.The fund may, to a limited extent, invest in privately held companies and companies that only recently began to trade publicly.At times, the fund may have a significant portion of its assets invested in the same economic sector. Principal Risks The fund’s share price fluctuates, which means you could lose money by investing in the fund. Mid-cap stocks: Investments in securities issued by mid-cap companies are likely to be more volatile than investments in securities issued by large-cap companies. Mid-cap companies may have less seasoned management, narrower product lines, and less capital reserves and liquidity than large-cap companies, and are therefore more sensitive to economic, market, and industry changes. Growth investing: The fund’s growth approach to investing could cause it to underperform other stock funds that employ a different investment style. Growth stocks tend to be more volatile than certain other types of stocks and their prices may fluctuate more dramatically than the overall stock market. A stock with growth characteristics can have sharp price declines due to decreases in current or expected earnings and may lack dividends that can help cushion its share price in a declining market. Stock investing: Stocks generally fluctuate in value more than bonds and may decline significantly over short time periods. There is a chance that stock prices overall will decline because stock markets tend to move in cycles, with periods of rising and falling prices. The value of stocks held by the fund may decline due to general weakness or volatility in the stock markets in which the fund invests or because of factors that affect a particular company or industry. Market conditions: The value of the fund’s investments may decrease, sometimes rapidly or unexpectedly, due to factors affecting an issuer held by the fund, particular industries, or the overall securities markets. A variety of factors can increase the volatility of the fund’s holdings and markets generally, including economic, political, or regulatory developments, recessions, inflation, rapid interest rate changes, war, military conflict, acts of terrorism, natural disasters, and outbreaks of infectious illnesses or other widespread public health issues (such as the coronavirus pandemic) and related governmental and public responses (including sanctions). Certain events may cause instability across global markets, including reduced liquidity and disruptions in trading markets, while some events may affect certain geographic regions, countries, sectors, and industries more significantly than others. Government intervention in markets may impact interest rates, market volatility, and security pricing. These adverse developments may cause broad declines in market value due to short-term market movements or for significantly longer periods during more prolonged market downturns. Sector exposure: Issuers in the same economic sector may be similarly affected by economic or market events, making the fund more vulnerable to unfavorable developments in that economic sector than funds that invest more broadly. Private placements and IPOs: Investments in the stocks of privately held companies and in companies that only recently began to publicly trade, such as initial public offerings or IPOs, involve greater risks than investments in stocks of companies that have traded publicly on an exchange for extended time periods. There is significantly less information available about these companies’ business models, quality of management, earnings growth potential, and other criteria that are normally considered when evaluating the investment prospects of a company. Private placements and other restricted securities held by the fund are typically considered to be illiquid and tend to be difficult to value since there are no market prices and less overall financial information available. The adviser evaluates a variety of factors when assigning a value to these holdings, but the determination involves some degree of subjectivity and the value assigned for the fund may differ from the value assigned by other mutual funds holding the same security. Liquidity: A particular investment or an entire market segment may become less liquid or even illiquid, sometimes abruptly, which could limit the fund’s ability to purchase or sell holdings in a timely manner at a desired price. An inability to sell a portfolio holding can adversely affect the fund’s overall value or prevent the fund from being able to take advantage of other investment opportunities. Liquidity risk may be magnified during periods of substantial market volatility and unexpected episodes of illiquidity may limit the fund’s ability to pay redemption proceeds without selling holdings at an unfavorable time or at a suitable price. Large redemptions may also have a negative impact on the fund’s overall liquidity. Active management: The fund’s overall investment program and holdings selected by the fund’s investment adviser may underperform the broad markets, relevant indices, or other funds with similar objectives and investment strategies. Cybersecurity breaches: The fund could be harmed by intentional cyberattacks and other cybersecurity breaches, including unauthorized access to the fund’s assets, confidential information, or other proprietary information. In addition, a cybersecurity breach could cause one of the fund’s service providers or financial intermediaries to suffer unauthorized data access, data corruption, or loss of operational functionality. Performance The following performance information provides some indication of the risks of investing in the fund. The fund’s performance information represents only past performance (before and after taxes) and is not necessarily an indication of future results. The following bar chart illustrates how much returns can differ from year to year by showing calendar year returns and the best and worst calendar quarter returns during those years for the fund’s Investor Class. Returns for other share classes vary since they have different expenses. The following performance information provides some indication of the risks of investing in the fund. The following bar chart illustrates how much returns can differ from year to year by showing calendar year returns and the best and worst calendar quarter returns during those years for the fund’s Investor Class. Returns for other share classes vary since they have different expenses. The following table shows the average annual total returns for each class of the fund that has been in operation for at least one full calendar year. The fund’s performance information included in the table is compared with a regulatory required index that represents an overall securities market (Regulatory Benchmark). In addition, the table may also include one or more indexes that more closely aligns to the fund’s investment strategy (Strategy Benchmark(s)). The fund’s performance information represents only past performance (before and after taxes) and is not necessarily an indication of future results. Calendar Year Returns <table cellpadding="0" cellspacing="0" style="border-collapse:collapse" width="100%"><tr style="font-size:1pt;"><td style="width:9.02%;"> </td><td style="width:14.01%;"> </td><td style="width:14.99%;"> </td><td style="width:13%;"> </td><td style="width:.49%;"> </td><td style="width:14.99%;"> </td><td style="width:14.99%;"> </td><td style="width:13%;"> </td><td style="width:5.5%;"> </td></tr><tr><td style="vertical-align:top; font-size:1pt;"> </td><td style="vertical-align:top; font-size:1pt;"> </td><td style="vertical-align:top;">Quarter Ended</td><td style="vertical-align:top;">TotalReturn</td><td style="vertical-align:top; font-size:1pt;"> </td><td style="vertical-align:top; font-size:1pt;"> </td><td style="vertical-align:top;">Quarter Ended</td><td style="vertical-align:top;">Total Return</td><td style="vertical-align:top; font-size:1pt;"> </td></tr><tr><td style="vertical-align:top; font-size:1pt;"> </td><td style="vertical-align:top; background-color:#E6E6E6;">Best Quarter</td><td style="vertical-align:top; background-color:#E6E6E6;">6/30/20</td><td style="vertical-align:top; background-color:#E6E6E6;">27.81%</td><td style="vertical-align:top; font-size:1pt;"> </td><td style="vertical-align:top; background-color:#E6E6E6;">Worst Quarter</td><td style="vertical-align:top; background-color:#E6E6E6;">3/31/20</td><td style="vertical-align:top; background-color:#E6E6E6;">-23.19%</td><td style="vertical-align:top; font-size:1pt;"> </td></tr></table> Best Quarter 2020-06-30 0.2781 Worst Quarter 2020-03-31 -0.2319 The following table shows the average annual total returns for each class of the fund that has been in operation for at least one full calendar year. The fund’s performance information included in the table is compared with a regulatory required index that represents an overall securities market (Regulatory Benchmark). In addition, the table may also include one or more indexes that more closely aligns to the fund’s investment strategy (Strategy Benchmark(s)).In addition, the table shows hypothetical after-tax returns to demonstrate how taxes paid by a shareholder may influence returns. After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as a 401(k) account or an IRA. After-tax returns are shown only for the Investor Class and will differ for other share classes. After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as a 401(k) account or an IRA. After-tax returns are shown only for the Investor Class and will differ for other share classes. Average Annual Total Returns Periods ended December 31, 2024 1992-06-30 0.0940 0.0778 0.1024 0.0709 0.0615 0.0848 0.0736 0.0604 0.0805 2015-08-28 0.0954 0.0792 0.1048 2000-03-31 0.0912 0.0749 0.0995 2002-09-30 0.0882 0.0720 0.0966 2020-03-16 0.1022 0.1712 Russell 3000® Index Russell 3000® Index (reflects no deduction for fees, expenses, or taxes) 0.1371 0.2381 0.1386 0.1255 0.2233 Russell Midcap Growth Index (reflects no deduction for fees, expenses, or taxes) 0.1231 0.2210 0.1147 0.1154 0.1961 Lipper Mid-Cap Growth Funds Index 0.0989 0.1073 0.0738 0.0934 0.1522 Updated performance information is available through troweprice.com. troweprice.com 485BPOS 2024-12-31 0000887147 false 2025-02-25 2025-03-01 N-1A ~ http://troweprice.com/20241231/role/RRSchedule4 ~ ~ http://troweprice.com/20241231/role/RRSchedule5 ~ ~ http://troweprice.com/20241231/role/RRSchedule6 ~ ~ http://troweprice.com/20241231/role/RRBarChart7 ~ ~ http://troweprice.com/20241231/role/RRSchedule8 ~ 0.0656 0.063 0.2486 -0.0204 0.3153 0.2417 0.1506 -0.2252 0.2011 0.094 ~ http://troweprice.com/20241231/role/RRSchedule9 ~ Subject to certain exceptions and account minimums, accounts are charged an annual $20 fee. T. Rowe Price Associates, Inc., has contractually agreed to waive and/or bear all the Z Class’ expenses (excluding interest; expenses related to borrowings, taxes, and brokerage; nonrecurring, extraordinary expenses; and acquired fund fees and expenses) in their entirety. T. Rowe Price Associates, Inc., expects this fee waiver and/or expense reimbursement arrangement to remain in place indefinitely, and the agreement may only be amended or terminated with approval by the fund’s Board of Directors. Due to new SEC Rules on shareholder reporting, the fund adopted a new broad-based securities market index, referred to as the Regulatory Benchmark. Return since 8/28/15. Return since 3/16/20.