Social Security delayed filing strategy at 70 - need Dec payment with 6-month retroactive benefits but worried about 2025 taxes

You need to apply about 3-4 months before you want your first payment. So if you want December as your first payment month, you should apply in August/September at the latest. Yes, you can do everything online including requesting retroactive benefits - it's just a section on the application where you specify your start month. For June, SSA pays benefits for the entire month regardless of what day your birthday falls on. So you'll get a full month for June. You're correct about the 6-month limit for retroactive benefits after FRA. There's no way to get 7 months of backpay, so you can't push it all to 2026. However, you could file in January 2026 for benefits to begin in December 2025, and request 5 months retroactive (July-November), leaving out June. This puts most of the lump sum in 2026 tax year.

I turned 70 last year and went through this EXACT situation!!! The SSA website says u need to file 3 months b4 u want benefits but I filed only 6 weeks before and still got my payment on time. Everything can be done online and its pretty straightforward except the retroactive part was confusing. Make SURE you indicate on the application that you want benefits to start in June not December!!!! They'll automatically pay you the back benefits for june-nov when they process evrything. BTW when u get the retroactive $$$$ be prepared for a BIG tax hit - I wasn't and it messed up my whole tax situation. 😡

You have to specifically request it on the application. There's a section that asks when you want benefits to begin. He needs to put August (his birthday month) not the current month when he applies. The system will recognize he's eligible for retroactive payments once they process it.

One thing you're missing - you should think about tax *brackets*, not just tax years. Getting all that backpay at once could push you into a higher tax bracket for whichever year you receive it. Since you're still working, you might want to calculate whether taking only 3 months retroactive now and then the other 3 months next year would keep you in a lower bracket each year. Also, be aware that your Social Security benefits are only taxable if your combined income (adjusted gross income + nontaxable interest + half of SS benefits) exceeds certain thresholds. For individuals, your benefits are taxable at 50% if combined income is $25,000-$34,000 and at 85% if over $34,000.

No you can't split retroactive payments that way. It's all or nothing for the months you're eligible for. But honestly just do what's best for you. The SSA doesn't care which month you choose as your start month as long as it's within the 6-month retroactive window after you reach 70.

Getting through to SSA to ask these kinds of nuanced questions can be incredibly frustrating. After wasting hours on hold myself, I discovered a service called Claimyr (claimyr.com) that got me connected to an agent in under 10 minutes. They have a video demo showing how it works at https://youtu.be/Z-BRbJw3puU. I was skeptical, but it saved me from the endless hold music and disconnections. If you need to talk through your specific situation with an actual SSA agent (which I'd recommend given your tax concerns), it might be worth checking out.

The agent I spoke with was knowledgeable about the SSA rules but was careful not to give tax advice specifically. They could confirm all the mechanics of how and when payments would be made, which helped me make my own tax decisions. I'd recommend having specific questions ready about the timing and payment processes rather than asking for tax strategy directly.

my sister just turned 70 and she said the online application was easy but it made her upload her birth certificate even tho shes been paying into ss her whole life! make sure u have a digital copy of urs ready

One more important point - since you're still working, be aware that your earnings won't affect your benefit amount once you've reached FRA (Full Retirement Age), which you have at 70. Unlike filing before FRA, there's no earnings test or benefit reduction. However, if your earnings are substantial, you may continue to increase your benefit amount slightly since SSA recalculates your benefit annually if your recent earnings are higher than some of the earnings used in your original calculation.

WAIT! Just remembered something important! When u get that retroactive payment, it'll be a separate deposit from your regular monthly payments going forward. Make SURE you set aside enough for taxes right away! I didn't and ended up scrambling. Also if it's a large amount it might affect your Medicare IRMAA surcharges for 2027 (based on 2025 income) if you're on Medicare.

Great point about IRMAA surcharges! That's something many people overlook. The Medicare high-income surcharges are based on your tax return from 2 years prior, so a large lump sum in 2025 could definitely impact your Medicare premiums in 2027. For someone in your situation still working with good income, you might want to run the numbers on whether spreading the benefit start over two tax years (like the January 2026 filing strategy mentioned earlier) could help you avoid crossing the IRMAA thresholds. The first IRMAA tier starts at $106,000 for individuals in 2025, and it goes up from there. Also, don't forget that if you do end up with a big tax bill from the retroactive benefits, you might need to make estimated tax payments to avoid underpayment penalties. The IRS doesn't care that it all came in one lump sum - they expect you to pay quarterly if you're going to owe more than $1,000.

As a newcomer to this community, I'm amazed at how many nuanced factors go into Social Security timing decisions! Reading through all these responses has been incredibly educational. @Dominic Green, your situation sounds similar to what my parents might face soon. One thing I'm wondering about - has anyone here worked with a tax professional specifically on Social Security timing strategies? With all these interconnected issues (IRMAA, estimated payments, bracket management, state taxes potentially), it seems like the complexity might warrant professional guidance beyond just calling SSA directly. Also, for those who've gone through this process, how accurate were your initial benefit estimates from the SSA website compared to what you actually received? I'm helping my parents plan and want to make sure we're working with realistic numbers for all these tax calculations. Thanks to everyone sharing their real experiences - it's so much more valuable than just reading the official SSA publications!