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.

T. Rowe Price Capital Opportunity R (RRCOX): 1.16% expense ratio and 0.32% management fee. RRCOX is classified as a Large Cap Blend fund. More often than not, Large Cap Blend mutual funds invest in companies with a market cap of over $10 billion. Buying stakes in bigger companies offer these funds more stability, and are well-suited for investors with a "buy and hold" mindset. RRCOX has achieved five-year annual returns of an astounding 12.41%.

Goldman Sachs International T/M Equity IR (GITRX Quick QuoteGITRX - Free Report) . Expense ratio: 0.96%. Management fee: 0.85%. GITRX is a Non US - Equity option, focusing their investments acoss emerging and developed markets, and can often extend across cap levels too. This fund has managed to produce a robust 11.71% over the last five years.

Allspring Disciplined Sm Cap A (WDSAX) is an attractive large-cap allocation. WDSAX is a Small Cap Blend mutual fund, allowing investors a way to diversify their funds among various types of small-cap stocks. WDSAX has an expense ratio of 1.27%, management fee of 0.5%, and annual returns of 11.71% over the past 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.