Are you fortunate enough to not yet need the withdrawal from your retirement account that the IRS is forcing you to take at some point during the year ahead? If so, congratulations! And don't sweat it. You've got several options for this money whenever you get it. Here's a closer look at the four top choices, one of which will almost certainly work for you.

What's a required minimum distribution?

Required minimum distributions (or RMDs) are taxable withdrawals that the IRS requires you to make from most kinds of individual retirement accounts (IRAs). Roth IRAs are exempt from RMD rules, of course, since contributions to Roth accounts weren't tax-deductible as they were being made, and distributions from these aren't taxed no matter when they're made.

As for how the "minimum" is calculated, it's a percentage of the previous year's ending value of your non-Roth IRA accounts, which gets bigger with age. Your first required distribution for the year in which you turn 73 is roughly a relatively modest 3.77% of your individual retirement accounts' balance as of the end of the prior year. If you're 85 years old, however, the required distribution is pumped up to 6.25% of the previous year-end value of your retirement accounts subject to RMDs. If you're 100, you'll need to withdraw about 15.62% of the IRA's value.

Your IRA's custodian or brokerage firm can help you determine your required distribution, although you don't necessarily have to take an RMD from every IRA you may own. The IRS only requires you to withdraw the correct total amount in any given tax year.

Also bear in mind that while your RMD is etched in stone, you can certainly remove more than the minimum. Just be careful. Again, these withdrawals are treated as taxable income. The bigger the distribution, the bigger the tax bill. If you're not careful, you could even bump yourself up into a higher tax bracket.

Here's a closer look at the four choices most retirees will want to make with RMDs they don't actually need yet, starting with the simplest and most obvious choice and progressing to the most complicated and most permanent.

1. Just hold the cash

While required distributions can be taken in the form of a transfer of stocks, bonds, funds, or other assets from an IRA (called an in-kind distribution), most people will receive the RMD in the form of cash. Feel free to leave it as cash until you decide to do something else more constructive with it, or at least until you might need to spend it.

Just be sure you're making the most of this cash. While most ordinary checking accounts and bank savings accounts are still paying next to nothing -- and far less than current inflation rates -- you can easily do better. Several online banks and most brokerage firms are currently paying in the ballpark of 4% to 5% on idle cash.

The only catch? In most cases, you'll need to give your broker or bank specific instructions to buy into these money market funds, and will need to provide instructions should you need to withdraw this money. Both transactions will take one business day to complete. It's certainly worth the little bit of time and trouble, though.

2. Reinvest it in a taxable account, rebalancing your overall portfolio in the process

Got something more fruitful in mind for this cash influx you don't need just yet but are getting anyway? Clearly, you can invest it -- or reinvest it -- however you see fit outside your retirement account. Just think strategically when you do.

Obviously, diversifying your portfolio is part of any good strategy. So, since you're already sitting on some idle cash and (probably) already poking around your accounts, now's an opportune time to check your overall allocation. Overloaded with tech growth stocks? Use your RMD money to scoop up some value names. No exposure to overseas markets? Go shopping for some foreign stocks.

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Perhaps the more fruitful way of figuring out how to reinvest your RMD, however, is recognizing that this money is no longer in a tax-sheltered account. Any buying or selling done with this capital now that it's not in an IRA is subject to taxation, as is any income -- like dividends -- it might produce in the meantime. If that's something you'd rather avoid, it makes sense to use this cash to make growth investments that typically don't cause a tax liability until you choose to sell. Conversely, maybe there's a strategic reason to specifically own highly taxable investments with this money.

3. Give it away

If you don't need your RMD right now and have good reason to think you never will, you can certainly give it away to a charitable cause. Such donations are also typically tax-deductible, offsetting the tax liability created by just taking your RMD. If all these numbers are relatively small, then the standard RMD/charitable giving rules are fine.

If your required distribution is going to be big and you're also looking to give away up to a six-figure sum, however, consider making an official qualified charitable distribution, or QCD.

QCDs are direct transfers from your IRA to a charitable cause, bypassing your hands altogether and therefore not even briefly becoming a taxable event. Qualified charitable contributions still satisfy the IRS' required minimum distribution rules, solving a problem before it becomes one. Individuals can make a QCD of up to $108,000 this year. Assuming both spouses each qualify, a married couple jointly filing a tax return can make up to $216,000 worth of qualified charitable contributions.

4. Put it toward a Roth conversion's tax bill

Finally, if you just never want to worry about determining and then facilitating a required minimum distribution again, you can put this money toward the tax bill that will come due by converting your current retirement savings to a Roth IRA.

If you regret not contributing to a Roth IRA earlier in life, you can make up for it now by converting some or all of your non-Roth retirement accounts to a Roth. Just bear in mind that you'll need to catch up with all the taxes you've been able to sidestep until now.

The amount of your ordinary retirement account that you wish to convert is 100% taxable as income the year in which the conversion is completed. You can use money from this account to cover the subsequent tax bill, but you may not want to, since that distribution would only add to your net tax liability. If you're taking an RMD anyway, you've at least got some extra cash to help cover the resulting increase in your income tax liability.

It's unlikely that one year's RMD would cover the entire tax bill for a conversion of all your ordinary retirement account(s) to a Roth, to be clear. Converting all your IRA money could also push you into a higher tax bracket. That's why many people choose to make these conversions in stages, as the cash to cover their tax cost becomes available without causing undue financial strain in the meantime.

Also bear in mind that there's a handful of so-called "five year" rules you'll need to be aware of regarding Roth conversions. You may find you're not eligible for such a conversion, or that the penalty is too steep. It's still a prospect worth exploring, though.