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, most reliable way to judge a mutual fund's quality over time is by analyzing its performance, diversification, and fees. The Zacks Mutual Fund Rank, which covers over 19,000 mutual funds, has helped us identify three outstanding options that are perfect for any long-term investors' portfolios that is retirement-focused.

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

AB Equity Income I (AUIIX Quick QuoteAUIIX - Free Report) has a 0.84% expense ratio and 0.55% management fee. AUIIX is a Large Cap Value mutual fund, which invests 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 12% over the last five years, this fund clearly wins.

T. Rowe Price Blue Chip Growth Adviser (PABGX Quick QuotePABGX - Free Report) . Expense ratio: 0.96%. Management fee: 0.55%. PABGX 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. This fund has managed to produce a robust 12.86% over the last five years.

Victory RS Global Growth A (RSGGX Quick QuoteRSGGX - Free Report) : 0.85% expense ratio and 0.6% management fee. RSGGX is a Global - Equity mutual fund investing in bigger markets like the U.S., Europe, and Japan; these kinds of funds aren't limited by geography. With a five-year annual return of 13.12%, this fund is a well-diversified fund with a long track record of success.

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.