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.

How can you tell a good mutual fund from a bad one? It's pretty basic: if the fund is diversified, has low fees, and shows strong performance, it's a keeper. Of course, there's a wide range, but using the Zacks Mutual Fund Rank, we've found three mutual funds that would be great additions to any long-term investors' portfolios.

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

Touchstone Premium Yield Equity Y (TPYYX Quick QuoteTPYYX - Free Report) : 0.9% expense ratio and 0.65% management fee. TPYYX is a part of the Non US - Equity fund category, many of which will focus across all cap levels, and will typically allocate their investments between emerging and developed markets. TPYYX has achieved five-year annual returns of an astounding 8.78%.

Vanguard Energy Admiral (VGELX). Expense ratio: 0.37%. Management fee: 0.35%. VGELX is a Sector - Energy mutual fund, which encompasses a wide range of vastly changing and vitally important industries throughout this massive global sector. This fund has managed to produce a robust 16.99% over the last five years.

American Funds Washington Mutual Investors F (WSHFX). Expense ratio: 0.62%. Management fee: 0.22%. Five year annual return: 14.87%. WSHFX 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.

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.