Which Tax Moves Expire on April 15 – Even If You File an Extension?
April 15 is nine days away, and most people treat it as a filing deadline. It is. But it’s also a hard cutoff for several tax moves that vanish whether you file on time or not. Filing an extension gives you until October 15 to submit your return. It does not give you more time to fund an IRA, contribute to an HSA, or avoid the estimated tax penalty for Q1 2026.
A tax-deadline contribution is money deposited into a qualifying retirement or health savings account on or before April 15 of the following year, applied retroactively to the prior tax year. For the 2025 tax year, that deadline falls on April 15, 2026. Miss it, and the opportunity to reduce your 2025 taxable income through these accounts is gone permanently.
Here’s what’s still available, what the limits are, and where the deadlines actually fall.
Is There Still Time to Fund a 2025 IRA?
Yes, but only until April 15. This deadline does not move with an extension.
For the 2025 tax year, you can contribute up to $7,000 to a traditional or Roth IRA ($8,000 if you’re 50 or older). If you haven’t maxed out your contributions yet, the window is still open for twelve more days.
The question for most high earners isn’t whether to contribute. It’s which type of IRA and whether you’re even eligible.
Roth IRA income limits for 2025: If your modified adjusted gross income (MAGI) is under $150,000 as a single filer or under $236,000 filing jointly, you can make a full contribution. The ability to contribute phases out between $150,000 and $165,000 for single filers, and between $236,000 and $246,000 for joint filers. Above those ceilings, direct Roth contributions aren’t eligible.
Traditional IRA deductibility: If you or your spouse are covered by a workplace retirement plan (ie. a 401(k), 403(b), or similar), the deduction for traditional IRA contributions begins phasing out at $79,000 MAGI for single filers and $126,000 for joint filers. Above $89,000 and $146,000 respectively, the deduction disappears entirely. You can still contribute, but the tax benefit of doing so depends on whether you need a deduction now or would rather have tax-free growth later.
For anyone above the Roth income limits, the backdoor Roth IRA – contributing to a non-deductible traditional IRA and then converting to Roth – remains an option. Just be aware of the pro-rata rule if you hold other pre-tax IRA balances: the IRS doesn’t let you cherry-pick which dollars you convert. The tax on the conversion is calculated based on the ratio of pre-tax to after-tax money across all your traditional IRA accounts.
This decision isn’t static. The right answer changes year to year as income, filing status, and existing IRA balances shift. It’s the kind of thing worth revisiting annually with your advisor.
Can You Still Contribute to an HSA for 2025?
Same deadline. If you were enrolled in a high-deductible health plan (HDHP) at any point during 2025, you may still have room to contribute to a health savings account for the 2025 tax year.
The 2025 HSA contribution limits are $4,300 for individual coverage and $8,550 for family coverage. If you were 55 or older at any point during 2025, you can add another $1,000 on top of that.
The HSA is the only account in the tax code that offers a triple tax advantage: contributions are tax-deductible, growth is tax-free, and withdrawals for qualified medical expenses are tax-free. For high earners who can afford to pay medical costs out of pocket and let the HSA grow, it functions as a stealth retirement account. There is no required minimum distribution, and after age 65, withdrawals for any purpose are taxed as ordinary income (similar to a traditional IRA) rather than penalized.
If you switched health plans mid-year or changed from individual to family coverage, the contribution limit is prorated based on months of HDHP eligibility. This is one of the areas where we frequently find unused capacity when reviewing a client’s full tax picture at Lotus Asset Management. Your plan administrator or CPA can help calculate the exact amount.
What About SEP-IRAs for Business Owners?
Here’s where the deadline works differently, and it matters.
A SEP-IRA (Simplified Employee Pension) allows self-employed individuals and small business owners to contribute up to 25% of net self-employment income, with a maximum of $70,000 for the 2025 tax year. That’s a significantly larger contribution than a traditional or Roth IRA allows.
The deadline for SEP-IRA contributions is tied to your tax filing deadline, including extensions. If you’re a sole proprietor or single-member LLC and you file an extension, you have until October 15, 2026 to make your 2025 SEP-IRA contribution. You can even establish a new SEP-IRA and fund it by that date.
The flexibility here is significant – both in contribution size and in timing. As a hypothetical: consider a consultant earning $280,000 in net self-employment income. After the self-employment tax adjustment, they could contribute roughly $52,000 to a SEP-IRA for 2025 – reducing their taxable income by that amount. If they haven’t set one up yet, they can open the account and fund it in a single step before the filing deadline.
One important distinction: SEP-IRA contributions are made by the employer (you, as the business owner), not by the employee. If you have employees, you generally must contribute the same percentage for them as you do for yourself. For solo operators, this isn’t an issue.
Did You Account for the New SALT Deduction Cap?
If you haven’t filed your 2025 return yet, this one is worth flagging with your tax preparer.
The One Big Beautiful Bill, signed into law on July 4, 2025, raised the state and local tax (SALT) deduction cap from $10,000 to $40,000, retroactive to January 1, 2025. For taxpayers in high-tax states (ie. California, New York, New Jersey, Connecticut), this is a meaningful change.
The new $40,000 cap applies to taxpayers filing jointly or as single filers. For married filing separately, the cap is $20,000. But there’s a phase-down for higher earners: the cap reduces by $0.30 for every dollar of MAGI above $500,000 ($250,000 for married filing separately), bottoming out at the old $10,000 floor.
Here’s a hypothetical to illustrate: a dual-income household in a high-tax state with a MAGI of $450,000 and combined state income tax plus property taxes of $35,000 was previously capped at a $10,000 deduction. For the 2025 return, they could deduct the full $35,000. That’s $25,000 in additional itemized deductions that weren’t available last year. (Actual results depend on your complete tax picture, including AMT exposure and other itemized deductions.)
If you filed early and used the old $10,000 cap (some preparers filed before the new guidance was fully digested), it’s worth asking your CPA whether an amended return makes sense given your specific situation.
Is Your Q1 2026 Estimated Tax Payment Set Correctly?
The first quarterly estimated tax payment for the 2026 tax year is also due April 15, 2026. This one catches people because it overlaps with the 2025 filing deadline. You’re simultaneously closing out one tax year and making the first payment toward the next.
For anyone who owes estimated taxes – business owners, freelancers, partners receiving K-1 income, employees with significant equity compensation or investment income not covered by withholding – getting Q1 right sets the tone for the year.
The IRS safe harbor rule for high earners: if your 2025 AGI exceeded $150,000, you must pay the lesser of 90% of your 2026 tax liability or 110% of your 2025 tax liability to avoid the underpayment penalty. The current underpayment penalty rate is running at ~7% annually, which is steep enough to matter on a large balance.
If your income is volatile (ie. you had a large equity vest in Q1, or your business had an unusually strong or weak start to the year), the annualized income installment method on Form 2210 may produce a lower required payment for Q1. This is worth asking your CPA about before you write the check.
In our experience at Lotus Asset Management, the situation that trips people up most often is when income structure changes between years. A new partnership distribution, a first-year RSU vest, selling a rental property – any of these can throw off a simple “pay what I paid last year” approach.
What Happens If You Miss the Deadline?
For IRA and HSA contributions: nothing can be done retroactively. The 2025 contribution window closes on April 15, 2026, and it does not reopen. You can still contribute for the 2026 tax year, but the 2025 opportunity is lost.
For estimated taxes: missing Q1 results in an underpayment penalty calculated on the shortfall, compounding daily at the current federal rate plus three percentage points. You can catch up with Q2 (due June 15, 2026), but the penalty on Q1 still accrues.
For your tax return itself: filing an extension is straightforward and carries no penalty, as long as you pay what you owe by April 15. The penalty is for late payment, not late filing. File Form 4868, estimate your balance due, and send the payment. The return itself can follow by October 15.
The twelve days between now and April 15 are worth more than most people realize. A few hours of attention to these items can materially affect both your 2025 tax bill and your 2026 planning trajectory.
As always, if any of this applies to your situation and you’d like to talk through the specifics, we’re here.
Frequently Asked Questions
Q: Can I still do a backdoor Roth IRA for 2025 if I’m over the income limit?
Yes. You can contribute to a non-deductible traditional IRA and convert it to a Roth IRA before or after April 15 – the contribution deadline applies to the initial IRA contribution, not the conversion. The key consideration is the pro-rata rule: if you have existing pre-tax IRA balances (from rollovers, prior deductible contributions, or SEP-IRA funds), the conversion will be partially taxable based on the ratio of pre-tax to after-tax money across all your traditional IRA accounts. This applies to 2025 contributions made by April 15, 2026.
Q: I already filed my 2025 return using the old $10,000 SALT cap. Should I amend?
It depends on whether the higher cap changes your tax liability. If your combined state and local taxes exceeded $10,000 and your MAGI is under $500,000, the new $40,000 cap likely means additional deductions you didn’t claim. Run the numbers with your CPA. If the difference is material (ie. more than a few hundred dollars), filing an amended return on Form 1040-X is straightforward and the IRS is processing these. If the difference is minor, the filing cost and effort may not justify it.
Q: Do I owe estimated taxes if all my income comes from a W-2?
Possibly. W-2 withholding covers the tax on your salary, but it doesn’t automatically account for investment income, rental income, or large capital gains from stock sales. If you exercised ISOs, sold RSUs at a gain, or had significant investment income in Q1 2026, your withholding alone may fall short. The IRS expects quarterly estimated payments to cover the gap. The safe harbor for high earners (AGI over $150,000) is to pay at least 110% of your prior year’s total tax liability through a combination of withholding and estimated payments.
