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.

T. Rowe Price US Large-Cap Core (TRULX Quick QuoteTRULX - Free Report) has a 0.64% expense ratio and 0.54% management fee. TRULX is a part of the Large Cap Growth mutual fund category, which invest in many large U.S. companies that are expected to grow much faster compared to other large-cap stocks. With yearly returns of 14.54% over the last five years, this fund clearly wins.

Janus Henderson Enterprise Institutional (JAAGX Quick QuoteJAAGX - Free Report) . Expense ratio: 0.72%. Management fee: 0.64%. JAAGX is a Mid Cap Growth mutual fund. These funds aim to target companies with a market capitalization between $2 billion and $10 billion that are also expected to exhibit more extensive growth opportunities for investors than their peers. This fund has managed to produce a robust 11.54% over the last five years.

Invesco Discovery A (OPOCX Quick QuoteOPOCX - Free Report) : 1.03% expense ratio and 0.6% management fee. OPOCX is one of many Small Cap Growth mutual funds; these funds tend to create their portfolios around stocks with market capitalization of less than $2 billion. The fund is mainly invested in equities, has a long reputation of salutary performance, and has yearly returns of 12.56% over the last 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.