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 easiest way to judge a mutual fund's quality over time is by analyzing its performance, diversification, and fees. Using the Zacks Mutual Fund Rank of over 19,000 mutual funds, we've identified three outstanding mutual funds that are ideally suited to help long-term investors pursue and achieve their retirement investing goals.

Let's break down some of the mutual funds with the top Zacks Mutual Fund Rank and the lowest fees.

Fidelity Select Tech Hardware (FDCPX Quick QuoteFDCPX - Free Report) : 0.72% expense ratio and 0.53% management fee. FDCPX is a Sector - Tech mutual fund, allowing investors to own a stake in a notoriously volatile sector with a much more diversified approach. With annual returns of 11.17% over the last five years, this fund is a winner.

AQR Large Cap Momentum Style R6 (QMORX Quick QuoteQMORX - Free Report) : 0.3% expense ratio and 0.25% management fee. QMORX 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 10.2% over the last five years, QMORX is an effectively diversified fund with a long reputation of solidly positive performance.

Schwartz Value Fund (RCMFX Quick QuoteRCMFX - Free Report) is an attractive large-cap allocation. RCMFX is a Small Cap Value fund, and these funds are known for investing in companies with market caps under $2 billion. RCMFX has an expense ratio of 1.25%, management fee of 0.75%, and annual returns of 14.1% 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.