It is never too late to invest in mutual funds for retirement. As such, if you plan to invest in some of the best funds, the Zacks Mutual Fund Rank can provide you with valuable guidance.

The easiest way to judge a mutual fund's quality over time is by analyzing its performance, diversification, and fees. Using the Zacks Mutual Fund Rank of over 19,000 mutual funds, we've identified three outstanding mutual funds that are ideally suited to help long-term investors pursue and achieve their retirement investing goals.

Let's break down some of the mutual funds with the top Zacks Mutual Fund Rank and the lowest fees.

Neuberger Berman Mid Cap Growth I (NBMLX Quick QuoteNBMLX - Free Report) : 0.67% expense ratio and 0.64% management fee. NBMLX is a Mid Cap Growth mutual fund. These funds aim to target companies with a market capitalization between $2 billion and $10 billion that are also expected to exhibit more extensive growth opportunities for investors than their peers. NBMLX has achieved five-year annual returns of an astounding 9.41%.

Transamerica Large Cap Value I (TWQIX): 0.63% expense ratio and 0.59% management fee. TWQIX is a part of the Large Cap Value category, and invests in equities with a market capitalization of $10 billion or more, but whose share prices do not reflect their intrinsic value. With yearly returns of 16.55% over the last five years, TWQIX is an effectively diversified fund with a long reputation of solidly positive performance.

American Funds Growth Fund of America R5E (RGAHX). Expense ratio: 0.44%. Management fee: 0.26%. Five year annual return: 13.41%. RGAHX is a Large Cap Growth option; these mutual funds purchase stakes in numerous large U.S. companies that are expected to develop and grow at a faster rate than other large-cap stocks.

There you have it. If your financial advisor had you put your money into any of our top-ranked funds, then they've got you covered. If not, you may need to talk.