Most people only think about retirement planning when HR sends a generic year-end email or when tax season rolls around and it’s already too late. The biggest wealth moves for retirement happen in December, and the deadlines hitting on December 31 will impact you or someone in your family in a very real way. These strategies are sitting on the table right now. Here’s how to use them before the window closes.
Match Out Your Day Job 401(k)
If you have a 401(k) through your employer, this deadline hits you first. When your company matches your contribution, you’re getting a one hundred percent return in one day. Put in four thousand and you instantly have eight thousand. Nothing in the stock market can touch that. Not Bitcoin. Not Tesla. Not Microsoft.
The mistake most people make is assuming they can only contribute through payroll during the year. Not true. If you’re behind on your contributions, you can still catch up before December 31.
Call HR and ask two simple questions:
1. How much have I contributed this year?
2. How much of the match have I unlocked?
Whatever you’re missing, you can send in before year-end by contribution or portal entry. Your employer will match it and you lock in free money. Match out first, then step back and decide whether you want to keep contributing or divert money to other strategies like a Roth IRA or Solo 401(k).
This move alone can put thousands back in your pocket.
Leverage the Mega Backdoor Roth
Once you match out, the next question is always the same. “I want to do more, so what next?” That is where the mega backdoor Roth comes in, and almost no one uses it because they don’t realize their plan allows it.
Your 401(k) lets you put in your regular employee contribution. Your employer matches it. But many plans also allow something called an after-tax employee contribution. This is the doorway to dropping up to seventy thousand per year into Roth dollars when structured correctly.
This strategy came from a group of oil rig workers up north who were making great money and needed a place to stash it. Their employer match was small and they hit the normal 401(k) limits fast, so they found a loophole in their plan that allowed after tax contributions they could convert to Roth the very next day with no tax due. They pushed tens of thousands through this route and built seventy thousand dollar Roth accounts year after year. It’s fully legal and backed by IRS guidance.
If your plan allows this after-tax contribution lane, the deadline to use it is December 31. Those dollars can then be converted in plan or rolled to a Roth IRA. And you get the most powerful tax-free bucket of money available.
This is a strategy for people who had a good year, received a bonus, liquidated something, or simply want to build tax-free wealth as aggressively as possible.
Make Your Year-End Roth Conversion
If you want any portion of your traditional IRA or 401(k) converted to Roth for the 2025 tax year, the conversion must be completed by December 31. The timing matters. And this year has created unique opportunities for people whose investments have pulled back or whose income is still within favorable bracket ranges.
There are two reasons to convert before year-end:
1. Your account value may be temporarily lower.
2. You want to control which tax year the conversion hits.
Many clients use a chunking strategy. Convert part this year. Convert part on January 1. Spread the tax hit. Stay inside a lower tax bracket. Or if you want to be aggressive, convert everything now and lock in your Roth bucket before the market moves.
And if you want your kids to fund a Roth IRA next spring, make sure they have earned income in their bank account before December 31. Funding can happen in March or April, but the income has to hit this year. Pay them now. Unlock their future tax free savings.
Bonus: Set Up Your Solo 401(k)
If you run a small business, this one is for you. A Solo 401(k) must be created by December 31 if you want full contribution options for 2025. Yes, there was a law change that lets you set up a plan after year-end, but you lose some major benefits if you wait, and you cannot maximize contributions the same way.
You also miss a powerful tax credit. Solo 401(k) plans qualify for a five hundred dollar credit each year for three years when you adopt the plan. That is fifteen hundred dollars in credits, not deductions, and it often covers most if not all of your setup cost.
Our internal deadline for a Solo 401(k) setup is December 15 because the IRS shuts down systems on December 26 each year. If you want the full deduction, the Roth option, the credit, and the ability to use your plan immediately, get it done before December 31.
A Solo 401(k) gives you far more flexibility than an IRA, and while it’s a bonus move, it’s the most valuable one on the list for many business owners.
The Bottom Line
These are the three retirement deadlines most people miss, and missing them costs real money. Matching out your 401(k). Taking advantage of the mega backdoor Roth. Setting up your Solo 401(k) before the window closes. Completing your Roth conversion while the brackets are still in your favor. These are the moves that create long term wealth and tax-free retirement income.
If you want these strategies applied to your exact situation before the deadlines hit, my team at KKOS Lawyers can meet with you on Zoom, review last year’s return, clean up your structure, and map out every move you should be making before December 31. And if a Solo 401(k) is on your radar, don’t miss our live webinar on December 3 at 12:00 PT. My team will walk you through the solo 401(k) tax credit for new and existing plans and show you how to set up your plan the right way while the IRS window is still open. If saving taxes and building long-term wealth matters to you, we’ll see you there.
