With most companies having done away with traditional pension plans, 401(k)s and other contribution-based retirement plans have become the norm.

And with their growing popularity comes growing scrutiny, with 401(k)s getting a lot of criticism over the years for having high fees that are hard even to discover.

That's about to change with your next 401(k) statement.

Now new rules require plans to give you a lot more information, including badly needed disclosures about how much you're really paying to sock away money for retirement.

When you get your next 401(k) statement at the end of September, here's a list of things to watch for, and some guidelines to help you judge your employer's retirement plan and make the best choices for your future:

1. How much you pay to invest.
Until now, you've often had to dig deep in order to find any information about the investment options you have within your 401(k). But the new rules make it much easier, requiring disclosure of total annual operating expenses, both in percentage terms and in raw dollars and cents for every $1,000 you have invested in your account.