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.

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.

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

If you are looking to diversify your portfolio, consider Victory Value Institutional (UIVAX). UIVAX 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. This fund is a winner, boasting an expense ratio of 0.88%, management fee of 0.68%, and a five-year annualized return track record of 13.08%.

Seafarer Overseas Value Instl (SIVLX Quick QuoteSIVLX - Free Report) : 1.05% expense ratio and 0.72% management fee. SIVLX is a Non US - Equity fund. Many of these funds like to allocate across emerging and developed markets, and will often focus on all cap levels. SIVLX, with annual returns of 13.06% over the last five years, is a well-diversified fund with a long track record of success.

SEI Inst Mgd Tr-Small Cap Value Y (SPVYX) is an attractive large-cap allocation. SPVYX is a Small Cap Value mutual fund option, which typically invest in companies with market caps under $2 billion. SPVYX has an expense ratio of 0.85%, management fee of 0.65%, and annual returns of 8.87% over the past five years.

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.