Year-End Tax Planning 2026: What to Do Before the Year Closes

Year-end tax planning means taking specific, dated steps before December 31 that lower what you owe or set you up for a smoother filing season, and for 2026 that includes new contribution limits and a higher standard deduction that change what moves actually help. This guide walks through what changed for 2026, a checklist for the self-employed and small business owners, the fourth-quarter estimated tax deadline, and the moves that depend on your personal or business situation.

This is general information, not advice for your situation.

What Year-End Tax Planning Is and Who It Affects

Year-end tax planning just means looking at your income, deductions and withholding before December 31 instead of waiting until you file next spring. Once the calendar turns, most of your options close. You can still gather receipts in March, but you cannot go back and make a retirement contribution that had to happen in 2026, or adjust your withholding for a year that already ended. The weeks between now and December 31 are the window where a few decisions can still change your 2026 tax bill.

This matters this year because the numbers themselves moved. For 2026, the standard deduction rises to $16,100 for single filers and married people filing separately, $32,200 for married couples filing jointly, and $24,150 for heads of household, and the extra amount for filers who are 65 or older or blind increases to $2,050 if single or head of household, or $3,300 for married couples filing jointly (IRS: 2026 Tax Brackets, Standard Deductions And Other Inflation Adjustments). Higher standard deductions can change whether itemizing still makes sense for you, which is one more reason to check your numbers now rather than after the year closes.

Three groups should pay attention before December 31. Individuals with wages, investment income or a life change such as a new job or a new dependent. The self-employed, who often have more moving pieces, including quarterly payments and retirement plan choices. And small business owners, who may have both personal and business decisions to make at once. If you fall into more than one of these groups, you are not alone, and it is worth working through the checklist below with your own numbers rather than someone else's. If you want a second set of eyes on where you stand, our tax help for individuals page is a good place to start.

2026 Thresholds: Retirement Contribution Limits and Tax Planning Strategies

Most of the easiest year-end tax planning strategies come down to one move: putting more money into a retirement account before December 31. The amount you are allowed to put in changes every year, so here are the 2026 numbers to work from.

If you have a 401(k) through work, you can defer up to $24,500 in 2026, up from $23,500 in 2025 (IRS: 401(k) limit increases to $24,500 for 2026, IRA limit increases to $7,500). This is the employee deferral limit, meaning it is the amount taken out of your own paycheck, separate from anything your employer contributes on top.

If you are 50 or older by the end of 2026, you can add a catch-up contribution of $8,000, bringing your total possible 401(k) deferral to $32,500 for the year (IRS: 401(k) limit increases to $24,500 for 2026, IRA limit increases to $7,500). There is a higher tier within that age bracket: if you turn 60, 61, 62 or 63 at any point in 2026, your catch-up limit is $11,250 instead of $8,000 (IRS: Retirement topics, 401(k) and profit-sharing plan contribution limits). These same catch-up rules apply to 403(b), governmental 457 and federal TSP plans, not just 401(k)s.

If you are contributing to a traditional or Roth IRA instead of, or in addition to, a workplace plan, the 2026 limit is $7,500, up from $7,000 in 2025. If you are 50 or older, you can add a $1,100 catch-up contribution, up from $1,000 in 2025 (IRS: 401(k) limit increases to $24,500 for 2026, IRA limit increases to $7,500). Unlike 401(k) contributions, which stop when your employer's last payroll of the year runs, you generally have until the tax filing deadline to fund an IRA for 2026, so this is one piece of year-end planning that does not have to be finished by December 31 itself.

Whether a traditional contribution, a Roth contribution, or a mix of both makes more sense depends on your income, your filing status and what other accounts you already have, which is exactly the kind of question worth sorting out with a professional before you decide where to send your next paycheck. If you want a second set of eyes on your specific numbers, our tax help for individuals page explains how a planning check-in works.

Year-End Tax Planning Checklist for Self-Employed Owners and HSA Holders

If you run your own business or work as a freelancer, a few of these limits apply only to you, so it is worth walking through them before December 31 rather than after. Here is what to check.

If you offer or use a SIMPLE 401(k)

First, check your SIMPLE 401(k) deferral for the year. If you run a small business with this type of plan, employees can defer up to $17,000 in 2026, and that limit adjusts for inflation most years (IRS: Retirement topics - 401(k) and profit-sharing plan contribution limits).

Second, if you or an employee will turn 50 or older by December 31, 2026, an extra $4,000 catch-up contribution is allowed on top of the regular limit. If the person is age 60, 61, 62 or 63 at any point in 2026, that catch-up amount rises to $5,250 instead (IRS: Retirement topics - 401(k) and profit-sharing plan contribution limits). A payroll run or two left in the year may not be enough time to hit these numbers, so check your year-to-date deferrals now, not in late December.

If you have an HSA or HDHP

Third, if you carry a health savings account (HSA), paired with a high-deductible health plan (HDHP), confirm how much room you have left for 2026. The contribution limit is $4,400 for self-only coverage and $8,750 for family coverage, both up slightly from 2025 (IRS Revenue Procedure 2025-19 (2026 HSA and HDHP limits)). An HSA contribution is one of the few moves you can still make after December 31 and have it count for the 2026 tax year, since the deadline follows the filing deadline rather than the calendar year, so do not assume the window is already closed. Fourth, if you are shopping for a plan or confirming your current one still qualifies, check that your HDHP meets the 2026 minimum deductible, at least $1,700 for self-only coverage or $3,400 for family coverage, and stays under the out-of-pocket maximum of $8,500 self-only or $17,000 family (IRS Announces 2026 HSA, HDHP Limits).

If you would rather have someone walk through these numbers with your specific business setup, our Business Tax Filings service covers this kind of year-end review.

Fourth-Quarter Estimated Tax Deadlines and the Safe-Harbor Rule

If you are self-employed, or you have income that does not have tax withheld from it, like rental income or investment gains, you likely pay estimated tax four times a year. For 2026, the payments are due April 15, June 15, and September 15, 2026, with the fourth and final payment for the year due January 15, 2027 (2026 Quarterly Tax Dates: Q1-Q4 IRS Payment Schedule). That January date is the one most people forget about in year-end planning, because by then the calendar has already flipped, but it still belongs to your 2026 tax year.

Underpaying your estimated tax during the year can lead to a penalty, even if you pay everything you owe by the April filing deadline. The way around this is called the safe harbor, and it is simpler than it sounds. If you pay, across your four estimated payments, at least 100% of your 2025 tax bill, or 110% of it if your 2025 adjusted gross income was over $150,000, or $75,000 if you are married filing separately, or at least 90% of what you will actually owe for 2026, you generally avoid the penalty (Quarterly Estimated Tax Payments 2026-2027: Dates, Worksheet, How to Pay).

Before December 31, it is worth running a rough estimate of your 2026 income and checking what you have paid in so far against both safe-harbor tests. If you are behind, you still have time to adjust your January payment, or increase withholding from a paycheck if you have one, since withholding is treated as paid evenly through the year regardless of when it actually happens. If this math feels unfamiliar, our tax help for individuals page explains how we help people get these numbers right before the January deadline, not after.

Year-End Tax Moves That Depend on Your Situation: Gifts, Estates and State Rules

Not every year-end move applies to every reader. Some of the most useful ones only matter if you are giving money away, running an estate plan, or filing in a state with its own calendar. Here is what to check before you assume a federal rule is the whole story.

If you plan to give money or property to family or anyone else before December 31, the annual gift tax exclusion for 2026 stays at $19,000 per recipient, the same as 2025. If your spouse is not a US citizen, you can give that spouse up to $194,000 in 2026 without it counting against your lifetime exemption (Morgan Lewis: IRS Announces Increased Gift and Estate Tax Exemption Amounts for 2026). Gifts under the per-recipient limit generally do not require a gift tax return at all, which makes year-end a natural time to use the exclusion before it resets on January 1.

For anyone thinking about larger transfers or estate planning, the lifetime gift and estate tax exemption is $15 million per individual in 2026 (Morgan Lewis: IRS Announces Increased Gift and Estate Tax Exemption Amounts for 2026). This is a federal number, and it works alongside the annual exclusion rather than replacing it. If your estate situation is anything but simple, this is a conversation for an estate attorney alongside your tax preparer, not a do-it-yourself year-end move.

State rules are not federal rules

One caution we repeat often: your state's estimated tax due dates, extension rules and even its own gift or estate tax may not match the federal calendar or thresholds at all. Some states tax gifts or estates differently, and some set their own quarterly payment dates. Before you finalize any year-end move, check your state's own tax agency site, or talk with us if you are not sure which rules apply to you. If your situation involves more than a straightforward individual return, our services for small businesses page covers how we help owners sort through filings that cross state lines.

Common Year-End Tax Planning Mistakes to Avoid

Most year-end tax mistakes are not about the law being complicated. They are about timing: a deadline passes in late December before you realize it mattered. Here are a few we see often.

Waiting too long on contribution windows

Retirement account deferrals through your paycheck have to happen before your last payroll of the year, not before April. If you want more taken out of your December checks, you need to tell your employer in November, not on December 30. Once the calendar turns, that window is closed for 2026 no matter how motivated you are in January.

Assuming a dependent's standard deduction works like yours

If you can claim your child or another relative as a dependent, their standard deduction is not the same flat amount everyone else gets. For 2026, it is capped at the greater of $1,350 or their earned income plus $450 (IRS: Revenue Procedure 2025-32, 2026 inflation adjustments). Parents sometimes assume a working teenager gets the full adult standard deduction and plan their own withholding or gifting around that. Check the actual number before you rely on it.

Trusting last year's rules on business deductions

Section 179 limits, bonus depreciation, and similar business write-off rules change from year to year and sometimes mid-year. Planning a big equipment purchase in December based on a number you remember from 2023 or 2024 is a common way to overestimate your deduction. Before you commit to a purchase for the tax benefit, confirm the current-year figure rather than assuming it carried over.

If you are not sure which numbers still apply to your business, our Business Tax Filings team can walk through your specific situation before you spend the money.

Your Year-End Tax Planning Checklist: What to Do Next

Before December 31, 2026 arrives, run through the pieces in order. First, check your retirement contributions. If you have a 401(k), 403(b), governmental 457 or TSP, make sure you are on track to hit the deferral limit for your age group, including the $8,000 catch-up for those 50 and older, or the higher $11,250 catch-up for ages 60 through 63 (IRS: Retirement topics, 401(k) and profit-sharing plan contribution limits). If you run a SIMPLE 401(k) for your small business, confirm employee deferrals against the 2026 limit as well (IRS: Retirement topics, 401(k) and profit-sharing plan contribution limits). Second, top off an IRA if you have room, up to $7,500 for 2026 (IRS: 401(k) limit increases to $24,500 for 2026, IRA limit increases to $7,500). Third, revisit the HSA, estimated payment and gifting items covered earlier in this post, since each has its own deadline.

For filing season, keep your pay stubs, 1099s, HSA statements, retirement contribution confirmations and any receipts tied to deductions you plan to claim. A little organization now saves time in the spring.

If you would rather have a second set of eyes on your 2026 numbers before the year closes, our individual estimator gives you a price for help in under a minute. Get my price in 30 seconds.

Frequently asked questions

What is the deadline for making 401(k), IRA and HSA contributions that count for the 2026 tax year?

Workplace 401(k) deferrals for 2026 must go through your paycheck by December 31, 2026, since you cannot make them after the year ends (IRS: 401(k) limit increases to $24,500 for 2026, IRA limit increases to $7,500). IRA and HSA contributions are more forgiving: you generally have until the 2026 tax filing deadline in April 2027 to make a contribution that still counts for 2026 (IRS Revenue Procedure 2025-19).

How much can a self-employed person or small business owner contribute to a SIMPLE 401(k) before year-end?

For 2026, the employee deferral limit for a SIMPLE 401(k) is $17,000 (IRS: Retirement topics, 401(k) and profit-sharing plan contribution limits). If you are 50 or older, you can generally add a catch-up contribution of $4,000, and if you are 60, 61, 62 or 63, that catch-up amount rises to $5,250 (IRS: Retirement topics, 401(k) and profit-sharing plan contribution limits). Check with your plan provider on timing before December 31.

Do I need to make a fourth-quarter estimated tax payment, and when is it due?

If you are self-employed or have income without withholding, you likely owe a fourth and final 2026 estimated payment, due January 15, 2027 (2026 Quarterly Tax Dates: Q1-Q4 IRS Payment Schedule). To sidestep an underpayment penalty, aim to pay at least 90 percent of your 2026 tax, or 100 percent of your 2025 tax (110 percent if your 2025 adjusted gross income topped $150,000, or $75,000 if married filing separately), spread across all four dates (Quarterly Estimated Tax Payments 2026-2027: Dates, Worksheet, How to Pay).

How much can I give to family members in 2026 without filing a gift tax return?

For 2026, you can give up to $19,000 per recipient without triggering a gift tax return, the same limit as 2025 (IRS Announces Increased Gift and Estate Tax Exemption Amounts for 2026). If your spouse is not a US citizen, the limit for gifts to them rises to $194,000 for 2026 (IRS Announces Increased Gift and Estate Tax Exemption Amounts for 2026). These are per-recipient limits, so you can give to multiple people each year without filing anything extra.

What is changing in the standard deduction for 2026 versus 2025?

For 2026, the standard deduction rises to $16,100 for single filers and married individuals filing separately, $32,200 for married couples filing jointly, and $24,150 for heads of household (IRS Announces 2026 Tax Brackets, Standard Deductions And Other Inflation Adjustments). If you or your spouse are 65 or older or blind, you can add $2,050 per qualifying condition for 2026 for single and head of household filers or $3,300 for married couples filing jointly (IRS Announces 2026 Tax Brackets, Standard Deductions And Other Inflation Adjustments).

How Portside can help

Running through a checklist is one thing, deciding which moves actually fit your return is another. If you want a second set of eyes before December 31, our Personal Tax Filings service is built for exactly this kind of year-end review, whether you are weighing a retirement contribution, an estimated payment, or a question about a dependent's return.

We work with individuals, freelancers and small business owners all year, not just in April, so a planning check-in in November or December is a normal part of what we do. Choose by December 31 and we can help you think through the rest of the year before it closes.

Curious what our help costs for your situation? Get your price in 30 seconds with our individual estimator.