Required minimum distributions (RMDs) can add thousands of dollars to your tax bill, even when done correctly. Done incorrectly, they can prove even more costly, so it's important to understand the rules surrounding these withdrawals before you move any money.

There are three major mistakes that can come back to bite you. They may not all apply to you right now, but keep them in mind in case they come up in future years.

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1. Failing to take your RMDs on time

You have until Dec. 31, 2026 to take your RMDs for the year if you'll be 74 or older by the end of the year. Those who turned 73 this year technically have until April 1, 2027, to take their first RMDs. However, if you wait until next year, you'll need to take two RMDs in 2027.

Failing to take your RMDs before the deadline will result in a 25% penalty on the amount you should have withdrawn. However, you can reduce this penalty to 10% if you correct the mistake and file an amended tax return within two years of the deadline.

2. Taking RMDs when you don't have to

You aren't required to take RMDs from Roth retirement accounts. These withdrawals won't count toward your taxable income for the year, so there's no reason for the government to force you to take the money out. Withdrawing money from these accounts could just cost you future investment growth you may have had if you'd left those savings alone.

You also aren't required to take withdrawals from your current 401(k) if you're still working and own less than 5% of the company. Skip withdrawals from this account until you retire if you're trying to keep your tax bill to a minimum.

3. Missing out on a tax-saving strategy for charitable donations

The IRS offers you one alternative to an RMD -- a qualified charitable distribution (QCD). This is where you donate your RMD to a charity instead of spending the money yourself. Done correctly, it fulfills your RMD requirement without raising your tax bill.

If you withdraw the money yourself and donate it to a charity, it doesn't count as a QCD. You must contact your plan administrator and say which organization you'd like to donate to. Then, it'll either cut you a check in the organization's name that you can pass along, or forward the money to the organization directly.

It's best not to wait until right before the RMD deadline to do this. Start thinking about making a QCD within the next few weeks to ensure it's completed on time.