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.

The best way to shortlist great mutual funds is to ensure solid performance, diversification, and low fees. Some are better than others, but utilizing the Zacks Mutual Fund Rank, we have identified three mutual funds that could be solid additions to one's retirement portfolio.

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

If you are looking to diversify your portfolio, consider Federated MDT Mid Cap Growth Institutional (FGSIX Quick QuoteFGSIX - Free Report) . FGSIX is a Mid Cap Growth mutual fund. These funds aim to target companies with a market capitalization between $2 billion and $10 billion that are also expected to exhibit more extensive growth opportunities for investors than their peers. This fund is a winner, boasting an expense ratio of 0.84%, management fee of 0.75%, and a five-year annualized return track record of 15.59%.

Fidelity Advisor Stock Select Allocation Cap Z (FZAPX Quick QuoteFZAPX - Free Report) : 0.5% expense ratio and 0.46% management fee. FZAPX 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. With yearly returns of 15.85% over the last five years, FZAPX is an effectively diversified fund with a long reputation of solidly positive performance.

AIC TS&W Equity Portfolio Institutional (TSWEX Quick QuoteTSWEX - Free Report) : 0.73% expense ratio and 0.58% management fee. TSWEX 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. The fund is mainly invested in equities, has a long reputation of salutary performance, and has yearly returns of 11.82% over the last five years.

We hope that your investment advisor (if you use one) has you invested in one or all of the top-ranked mutual funds we've reviewed. But if that isn't the case, it might be time to have a conversation or reconsider this vitally important relationship.