There is never a wrong time to invest in mutual funds for retirement. So, if you're still looking for the best mutual funds, the Zacks Mutual Fund Rank can be a great guide.

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 take a look at some of our top-ranked mutual funds with the lowest fees.

Federated International Small-Mid Company A (ISCAX Quick QuoteISCAX - Free Report) has a 1.24% expense ratio and 0.9% management fee. ISCAX is a Non US - Equity option, focusing their investments acoss emerging and developed markets, and can often extend across cap levels too. With yearly returns of 10.64% over the last five years, this fund clearly wins.

Janus Henderson Global Technology D (JNGTX): 0.78% expense ratio and 0.64% management fee. With a much more diversified approach, JNGTX--part of the Sector - Tech mutual fund category--gives investors a way to own a stake in the notoriously risky tech sector. With yearly returns of 16.72% over the last five years, JNGTX is an effectively diversified fund with a long reputation of solidly positive performance.

Empower Smal Cap Value Inv (MXLSX): 1.09% expense ratio and 0.71% management fee. MXLSX is categorized as an All Cap Value fund, and like the name suggests, invests across the cap spectrum in small-cap, mid-cap, and large-cap companies. With a five-year annual return of 13.21%, this fund is a well-diversified fund with a long track record of success.

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.