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 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.

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

ClearBridge Large Cap Value IS (LMLSX Quick QuoteLMLSX - Free Report) : 0.6% expense ratio and 0.49% management fee. LMLSX is a part of the Large Cap Value category, and invests in equities with a market capitalization of $10 billion or more, but whose share prices do not reflect their intrinsic value. LMLSX has achieved five-year annual returns of an astounding 13.15%.

Bridges Investment Fund (BRGIX Quick QuoteBRGIX - Free Report) : 0.75% expense ratio and 0.5% management fee. BRGIX 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 17.35% over the last five years, BRGIX is an effectively diversified fund with a long reputation of solidly positive performance.

Empower Small Cap Growth Instl (MXMSX Quick QuoteMXMSX - Free Report) is an attractive large-cap allocation. MXMSX is a Small Cap Growth mutual fund building their portfolio around stocks with market caps under $2 billion and large growth opportunities. MXMSX has an expense ratio of 0.84%, management fee of 0.83%, and annual returns of 11.75% 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.