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.

American Funds Fundamental Investors R3 (RFNCX) has a 0.92% expense ratio and 0.24% management fee. RFNCX is a Large Cap Blend fund, targeting companies with market caps of over $10 billion. These funds offer investors a stability, and are perfect for people with a "buy and hold" mindset. With yearly returns of 11.74% over the last five years, this fund clearly wins.

Columbia Seligman Tech/Info Inst3 (CCOYX): 0.82% expense ratio and 0.81% management fee. CCOYX is a Sector - Tech mutual fund, allowing investors to own a stake in a notoriously volatile sector with a much more diversified approach. With yearly returns of 18.18% over the last five years, CCOYX is an effectively diversified fund with a long reputation of solidly positive performance.

Alger Focus Equity A (ALAFX Quick QuoteALAFX - Free Report) : 0.99% expense ratio and 0.52% management fee. ALAFX 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 a five-year annual return of 15.76%, this fund is a well-diversified fund with a long track record of success.

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.