It is never too late to invest in mutual funds for retirement. As such, if you plan to invest in some of the best funds, the Zacks Mutual Fund Rank can provide you with valuable guidance.

The easiest, most reliable way to judge a mutual fund's quality over time is by analyzing its performance, diversification, and fees. The Zacks Mutual Fund Rank, which covers over 19,000 mutual funds, has helped us identify three outstanding options that are perfect for any long-term investors' portfolios that is retirement-focused.

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

Victory Pioneer Global Equity Y (PGSYX): 0.75% expense ratio and 0.65% management fee. PGSYX is a Global - Equity mutual fund investing in bigger markets like the U.S., Europe, and Japan; these kinds of funds aren't limited by geography. PGSYX has achieved five-year annual returns of an astounding 15.51%.

Fidelity Advisor Stock Select Allocation Cap M (FSJHX): 1.07% expense ratio and 0.53% management fee. FSJHX 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. With yearly returns of 12.62% over the last five years, FSJHX is an effectively diversified fund with a long reputation of solidly positive performance.

Bridgeway Omni Small Cap Value Fund (BOSVX Quick QuoteBOSVX - Free Report) . Expense ratio: 0.47%. Management fee: 0.45%. Five year annual return: 10.28%. BOSVX is a Small Cap Value mutual fund, investing in small companies with stock market valuation less than $2 billion.

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.