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.

Here are the funds that have achieved the Zacks Mutual Fund Rank #1 (Strong Buy) and have low fees.

Fidelity Equity Dividend Income K (FETKX Quick QuoteFETKX - Free Report) : 0.49% expense ratio and 0.42% management fee. FETKX 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 annual returns of 10.43% over the last five years, this fund is a winner.

First Eagle Gold Fund I (FEGIX Quick QuoteFEGIX - Free Report) : 0.94% expense ratio and 0.75% management fee. FEGIX is a Sector - Precious Metal mutual fund, typically investing in companies that are involved in the mining and production of precious metals like gold, silver, platinum, and palladium. FEGIX, with annual returns of 8.58% over the last five years, is a well-diversified fund with a long track record of success.

State Street Institutional US Equity Services (SUSSX Quick QuoteSUSSX - Free Report) : 0.65% expense ratio and 0.39% management fee. SUSSX is a Large Cap Blend fund, targeting companies with market caps of over $10 billion. These funds offer investors a stability, and are perfect for people with a "buy and hold" mindset. The fund is mainly invested in equities, has a long reputation of salutary performance, and has yearly returns of 15% over the last 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.