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.

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

Bridgeway Small Cap Value N (BRSVX Quick QuoteBRSVX - Free Report) : 0.78% expense ratio and 0.61% management fee. BRSVX is a Small Cap Value mutual fund, investing in small companies with stock market valuation less than $2 billion. With annual returns of 14.08% over the last five years, this fund is a winner.

Red Oak Technology Select (ROGSX Quick QuoteROGSX - Free Report) . Expense ratio: 0.91%. Management fee: 0.74%. With a much more diversified approach, ROGSX--part of the Sector - Tech mutual fund category--gives investors a way to own a stake in the notoriously risky tech sector. This fund has managed to produce a robust 14.3% over the last five years.

Voya Large Cap Growth I (PLCIX Quick QuotePLCIX - Free Report) : 0.62% expense ratio and 0.51% management fee. PLCIX 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. The fund is mainly invested in equities, has a long reputation of salutary performance, and has yearly returns of 12.59% over the last 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.