There is never a wrong time to invest in mutual funds for retirement. So, if you're still looking for the best mutual funds, the Zacks Mutual Fund Rank can be a great guide.

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 Advisor Balanced Fund I (FAIOX Quick QuoteFAIOX - Free Report) has a 0.56% expense ratio and 0.38% management fee. FAIOX is a part of the Allocation Balanced fund category; these funds like to invest in a variety of asset types, finding a balance between stocks, bonds, cash, and sometimes even precious metals and commodities; they are mostly categorized by their respective asset allocation. With yearly returns of 11.94% over the last five years, this fund clearly wins.

Principal Mid Cap A (PEMGX Quick QuotePEMGX - Free Report) . Expense ratio: 0.95%. Management fee: 0.58%. PEMGX 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 12.19% over the last five years.

Vanguard Growth & Income Investor (VQNPX Quick QuoteVQNPX - Free Report) is an attractive large-cap allocation. VQNPX is classified as a Large Cap Blend fund. More often than not, Large Cap Blend mutual funds invest in companies with a market cap of over $10 billion. Buying stakes in bigger companies offer these funds more stability, and are well-suited for investors with a "buy and hold" mindset. VQNPX has an expense ratio of 0.34%, management fee of 0.31%, and annual returns of 15.93% 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.