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.

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

Principal Large Cap Growth I R3 (PPUMX Quick QuotePPUMX - Free Report) : 1.16% expense ratio and 0.6% management fee. PPUMX 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. PPUMX has achieved five-year annual returns of an astounding 13.59%.

Fidelity Select Semiconductors (FSELX Quick QuoteFSELX - Free Report) . Expense ratio: 0.68%. Management fee: 0.53%. FSELX is a Sector - Tech mutual fund, allowing investors to own a stake in a notoriously volatile sector with a much more diversified approach. This fund has managed to produce a robust 33% over the last five years.

GMO Quality III (GQETX Quick QuoteGQETX - Free Report) is an attractive large-cap allocation. GQETX 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. GQETX has an expense ratio of 0.5%, management fee of 0.48%, and annual returns of 15.96% over the past five years.

These examples highlight the fact that there are some astonishingly good mutual funds out there. If your advisor has you in the good ones, bravo! If not, you may need to have a talk.