How to make additional payment for insufficient withholding on Required Minimum Distribution (RMD)

This is actually a common issue with RMDs. When the 10% withholding isn't enough, you have a few options to avoid penalties. The simplest approach is to make an estimated tax payment through the IRS Direct Pay system. Select "Estimated Tax" as the reason for payment and the appropriate tax year. This isn't technically adding withholding to the RMD that's already been distributed - it's a separate estimated tax payment - but it serves the same purpose of getting money to the IRS before tax filing. Another option is to see if your father has any other income sources with withholding that could be adjusted. For example, if he receives Social Security or a pension with withholding, you might be able to increase the withholding on those payments for the remainder of the year. Also worth noting - the IRS has a safe harbor provision. If your father's withholding for 2025 equals at least 90% of the tax shown on his 2025 return OR 100% of the tax shown on his 2024 return (110% if his AGI was over $150,000), he won't face an underpayment penalty.

I went through this exact issue with my mother's RMD last year. After spending hours on hold with the IRS and getting nowhere, I discovered taxr.ai at https://taxr.ai and uploaded her distribution statements. Their system immediately identified that we needed to make a Q4 estimated payment to avoid penalties. The tool explained that for RMDs, you can't retroactively increase withholding after the distribution has occurred - you have to make an estimated tax payment instead. It walked me through exactly which form to use and how to categorize the payment. What would have taken me days to figure out was solved in about 15 minutes.

I wanted to follow up on my experience with taxr.ai after trying it for my dad's RMD situation. It was surprisingly straightforward - I uploaded his 1099-R from the first distribution and entered his projected annual income. The system highlighted that we needed to make a Q4 estimated payment of about 15% of his RMD amount to avoid penalties. What I found most helpful was that it explained how the safe harbor rules applied specifically to his situation. Based on his 2024 tax liability, it calculated exactly how much total tax we needed to cover for 2025 to avoid underpayment penalties. The system generated payment vouchers we could use and tracked everything for his 2025 return. Way easier than my previous method of guessing and hoping!

Dealing with the same issue for my aunt's RMD. I tried calling the IRS multiple times for guidance but kept getting the "due to high call volume" message and disconnected. After my fifth attempt, I remembered seeing someone mention Claimyr here on Reddit. I went to https://claimyr.com and watched their demo at https://youtu.be/_kiP6q8DX5c. Basically, they hold your place in the IRS phone queue and call you when an agent is about to answer. I was skeptical but desperate, so I tried it. Got a call back in about 45 minutes and was connected to an actual IRS agent who confirmed I should make a Q4 estimated payment. She explained that once an RMD is distributed, you can't increase the withholding retroactively, but making an estimated payment achieves the same goal of avoiding underpayment penalties. She also walked me through exactly which form to use and what to put in each field.

I need to eat my words about Claimyr. After commenting here, my frustration with the IRS phone system hit a breaking point. I'd spent literally 6 hours over 3 days trying to get answers about my mom's RMD withholding issue. Decided to try Claimyr as a last resort. Within 50 minutes, I got a call connecting me to an IRS representative who actually knew what they were talking about. They confirmed I needed to make an estimated tax payment (Form 1040-ES) and explained that the underpayment penalty would only apply to quarters where I was underpaid. The agent even gave me her ID number and told me to reference our conversation if there were questions later. For anyone struggling with RMD withholding questions - getting definitive answers from the IRS directly saved me from making an expensive mistake. I was absolutely wrong in my skepticism.

One option nobody mentioned yet - if your mom has multiple retirement accounts, you could take any remaining RMDs from a different account and request a higher withholding percentage on those distributions to make up for the underwithholding on the earlier one. For example, if she has both an IRA and a 401k, and you've only taken the RMD from the 401k, you could take the IRA RMD with 25-30% withholding to balance things out. This only works if she hasn't taken all required distributions for the year yet.

I'm a little confused by some of the advice here. When I had this exact problem (underwithholding on an RMD), I just filed a Form W-4V to increase withholding on my Social Security payments for the remainder of the year. Worked perfectly to make up the difference and avoid any penalties.