Source: Social Security Administration.

If you're a woman, I've got good news and bad news when it comes to retirement planning.

The good news is that despite the fact that, on average, you earn as much as 40% less than males and spend considerably less time in the workforce -- usually to care for a child or an elderly family member -- you are out-saving most of your male brethren for retirement. Considering the additional obstacles, that's a huge deal.

But the bad news -- aside from the aforementioned wage and time-in-the-workforce disparity -- is that among those earning above $100,000, women are leagues behind their male counterparts.

That's according to an annual study released by Vanguard. Here's what the company found, and how -- if you're a woman -- you can help make up the difference in your retirement accounts.

The big picture
When we look at the whole of Vanguard's release, the headline finding is that men simply have far more money invested in their 401(k)s than women do -- by a magnitude of 50% -- and they earn about 40% more per year.

Clearly, a host of factors are combining to make the retirement planning process far more difficult for women.

Going beyond the knee-jerk reaction
It would be easy to simply throw our arms up and say, "The system is rigged from the get-go." But if we delve a little deeper into the findings, we see some important distinctions.

First and foremost, women's approach to retirement planning is sound. On average, they participate more in defined-contribution plans and save more of their salary every year for retirement. Women are also more willing to allow professionals to manage that money. Over time, that professional management (especially considering that it comes from Vanguard) yields better results than the do-it-yourself approach many males try without the proper training.

In fact, when we look at all individuals earning less than $100,000 per year -- about 96% of Americans -- women are doing a better job of saving for retirement. It is only when we consider the country's top earners that we see disparity creep in.

When it comes to the vast majority of wage earners in the United States, such parity in retirement savings should provide a ray of hope.

Where the problem lies
From the data Vanguard provides, it's clear that once we begin looking at the upper echelons of wage earners, men have a marked advantage over women.

The most demonstrable reason for this disparity is that women -- on average -- spend 12 fewer years in the workforce than men. Most importantly, these breaks in continuity make it increasingly difficult for women to get the types of promotions that lead to jobs paying over $100,000 per year.

For women who find themselves in this position -- entering the upper echelons of society and wishing to maintain an equal footing with men's retirement portfolios -- there are a few key steps that can be taken.

First, approach investing with a decades-long time frame. Remember, as a woman, you'll likely live longer than the average man and will thus need your money to last longer.

And second, be willing to invest more aggressively. Though that usually means a more volatile ride, volatility isn't the same as risk when you're willing to hold for the long term and not panic. Over a long enough time frame, you will earn higher returns for this higher risk, and it can help you keep pace with your male counterparts. So don't trade the risk of short-term losses for the risk of running out of money in what will hopefully be a long retirement.

Either way, the message from the Vanguard report is clear: Women are doing a great job saving for retirement. And if they weren't taking time off to care for family members, they would be head and shoulders above men when it comes to retirement planning.