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 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.

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

Brown Advisory Flexible Equity Institutional (BAFFX Quick QuoteBAFFX - Free Report) : 0.54% expense ratio and 0.43% management fee. BAFFX is classified as an Allocation Balanced fund, which seeks to invest in a balance of asset types, like stocks, bonds, and cash, and including precious metals or commodities is not unusual. BAFFX has achieved five-year annual returns of an astounding 12.28%.

Fidelity Growth & Income Portfolio (FGRIX Quick QuoteFGRIX - Free Report) . Expense ratio: 0.58%. Management fee: 0.42%. FGRIX is part of the Large Cap Blend section, and these mutual funds most often invest in firms with a market capitalization of $10 billion or more. By investing in bigger companies, these funds offer more stability, and are often well-suited for investors with a "buy and hold" mindset. This fund has managed to produce a robust 10.94% over the last five years.

MassMutual Premier Disciplined Growth A (MPGAX Quick QuoteMPGAX - Free Report) . Expense ratio: 1.18%. Management fee: 0.45%. Five year annual return: 11.47%. MPGAX is a Large Cap Growth mutual fund, and these funds invest in many large U.S. firms that are projected to grow at a faster rate than their large-cap peers.

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.