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.

MFS Blended Research Value Equit R6 (BRUNX Quick QuoteBRUNX - Free Report) : 0.42% expense ratio and 0.4% management fee. BRUNX is a Large Cap Value fund. These funds invest in stocks with a market cap of $10 billion of more, but whose share prices do not reflect their intrinsic value. With annual returns of 14.46% over the last five years, this fund is a winner.

Fidelity Growth Company (FDGRX). Expense ratio: 0.65%. Management fee: 0.51%. FDGRX 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. This fund has managed to produce a robust 15.07% over the last five years.

Segall Bryant & Hamilton International Small I (SBSIX) is an attractive large-cap allocation. SBSIX is a part of the Non US - Equity fund category, many of which will focus across all cap levels, and will typically allocate their investments between emerging and developed markets. SBSIX has an expense ratio of 1.06%, management fee of 0.9%, and annual returns of 13.85% over the past five years.

There you have it. If your financial advisor had you put your money into any of our top-ranked funds, then they've got you covered. If not, you may need to talk.