Investing in mutual funds for retirement is never too late. And the Zacks Mutual Fund Rank can be an excellent tool for investors looking to invest in the best funds.

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 take a look at some of our top-ranked mutual funds with the lowest fees.

American Beacon Large Cap Value Institutional

(AADEX Quick QuoteAADEX - Free Report) has a 0.65% expense ratio and 0.55% management fee. AADEX is a Large Cap Value fund. These funds invest in stocks with a market cap of $10 billion of more, but whose share prices do not reflect their intrinsic value. With yearly returns of 10.34% over the last five years, this fund clearly wins.

Janus Henderson Research I

(JRAIX Quick QuoteJRAIX - Free Report) : 0.64% expense ratio and 0.48% management fee. JRAIX is a Large Cap Growth mutual fund, and these funds invest in many large U.S. firms that are projected to grow at a faster rate than their large-cap peers. With yearly returns of 16.76% over the last five years, JRAIX is an effectively diversified fund with a long reputation of solidly positive performance.

AQR Small Cap Momentum Style R6

(QSMRX Quick QuoteQSMRX - Free Report) is an attractive large-cap allocation. QSMRX is one of many Small Cap Growth mutual funds; these funds tend to create their portfolios around stocks with market capitalization of less than $2 billion. QSMRX has an expense ratio of 0.52%, management fee of 0.45%, and annual returns of 10.26% over the past five years.

These examples highlight the fact that there are some astonishingly good mutual funds out there. If your advisor has you in the good ones, bravo! If not, you may need to have a talk.