The deadlines that matter most between now and spring are December 31, 2026, January 15, 2027, and April 15, 2027.
- December 31, 2026: year-end moves.
- January 15, 2027: the last 2026 estimated tax payment.
- April 15, 2027: 2026 returns, IRA and HSA contributions, and extensions.
Around those three sit enrollment windows and tax-form dates. Then there are the deadlines that start when something happens to you, not on a calendar date: an equity grant, a rollover, an inheritance, a 65th birthday.
When a federal tax date falls on a weekend or legal holiday, it moves. IRS Publication 509 puts it this way: “the act is considered to be performed timely if it is performed no later than the next day that isn’t a Saturday, Sunday, or legal holiday.” Every date below already reflects that rule.
What are the tax and financial deadlines from October 2026 to April 2027?
| Date | Deadline | Who |
|---|---|---|
| Thu, Oct 15, 2026 | Extended 2025 returns, Medicare enrollment opens | Form 4868 filers, Medicare enrollees |
| Sun, Nov 1, 2026 | HealthCare.gov enrollment opens | Marketplace buyers |
| Mon, Dec 7, 2026 | Medicare enrollment ends | Medicare enrollees |
| Tue, Dec 15, 2026 | Last sign-up for Jan 1 coverage | Marketplace buyers |
| Thu, Dec 31, 2026 | Year-end moves (next section) | Most households |
| Fri, Jan 15, 2027 | Q4 estimated tax, HealthCare.gov enrollment ends | Self-employed, investors, equity holders |
| Mon, Feb 1, 2027 | W-2s and Forms 3921, 3922 arrive | Employees, ISO and ESPP holders |
| Tue, Feb 16, 2027 | 1099-Bs arrive | Anyone who sold investments |
| Mon, Mar 15, 2027 | Partnership and S corp K-1s, unless extended | Business owners, fund investors |
| Thu, Apr 1, 2027 | First RMD if you turned 73 in 2026 | Retirees born in 1953 |
| Thu, Apr 15, 2027 | 2026 returns or extension, IRA and HSA contributions, Q1 estimate | Nearly everyone |
| Fri, Oct 15, 2027 | Extended 2026 returns due | Form 4868 filers |
Two of those dates moved:
- W-2s and Forms 3921 and 3922: your employer owes you a W-2, and your company owes you Form 3921 (for an ISO exercise) or Form 3922 (for an ESPP purchase), by January 31, which is a Sunday in 2027.
- 1099-Bs: brokers owe 1099-B statements by February 15, which is Washington’s Birthday, a federal holiday.
State filing dates, state estimated payments, and employer open enrollment all vary. Open enrollment usually runs in the fall on dates your employer sets. It is often your only chance each year to change your health plan, FSA, or dependent-care election.
What has to be done by December 31, 2026?
Anything that has to happen inside the 2026 tax year. Only a few contributions can wait until after year-end.
| Move | By December 31 | Details |
|---|---|---|
| RMDs | Withdraw full 2026 RMD | A first RMD can wait to Apr 1, 2027 |
| 401(k) deferrals | Out of 2026 paychecks | Last payroll date, often before Dec 31 |
| Tax-loss harvesting | Trade by Dec 31 | Wash-sale window runs into January |
| Roth conversions | Completed in 2026 | Taxed as 2026 income, can’t be undone |
| Charitable gifts, QCDs | Delivered or charged | QCDs start at age 70½ |
| 529 state deduction | Most states: contribute in 2026 | Some allow later, Wisconsin to Apr 15, 2027 |
| Annual gift exclusion | Up to $19,000 per recipient | Unused amount doesn’t carry over |
| Health FSA | Spend 2026 balance | Plan may allow 2½-month grace or $680 carryover |
A few of these need more detail.
RMDs. The IRS RMD rules say that “for each year after your required beginning date, you must withdraw your RMD by December 31.” If you push a first RMD to April 1, you take two distributions in the same tax year.
The RMD calculator estimates this year’s amount.
Loss harvesting. A sale on December 28 counts for 2026. But if you buy the same or a substantially identical security through January 27, the wash-sale rule in IRS Publication 550 can disallow the loss.
Check dividend reinvestment and any IRA purchases too. Tax-loss harvesting walks through the window.
Roth conversions. Since 2018 you cannot recharacterize a conversion, per IRS Publication 590-A, so model the tax before you convert.
If you do a backdoor Roth, the pro-rata math uses your traditional, SEP, and SIMPLE IRA balances on December 31 of the conversion year. That means a late-year rollover into an IRA can make part of the conversion taxable.
Charitable gifts. According to IRS Publication 526, contributions “charged on your bank credit card are deductible in the year you make the charge.”
- A stock certificate counts on the date it is mailed or delivered.
- Brokerage transfers of shares can take days, so start them in early December.
The 2026 changes to charitable deductions, including the new 0.5% of AGI floor for itemizers, are covered in 2026 tax changes.
529 plans. The deadline depends on your state. Wisconsin’s Schedule CS instructions, for example, accept contributions for a tax year through April 15 of the following year. Check your own state’s plan before you assume you have until spring.
FSAs. For 2026 plan years, Rev. Proc. 2025-32 caps health FSA salary reductions at $3,400 and carryovers at $680. The dependent-care FSA limit rose to $7,500 starting in 2026 under 26 U.S.C. 129, so check the amount you elect in open enrollment.
When are 2026 estimated tax payments due?
Form 1040-ES sets four dates:
- April 15, 2026
- June 15, 2026
- September 15, 2026
- January 15, 2027
The form adds one exception: “You don’t have to make the payment due January 15, 2027, if you file your 2026 tax return by February 1, 2027, and pay the entire balance due with your return.” Few people with K-1s or a late 1099-B can file that early, so plan on the January payment.
To avoid the underpayment penalty, pay at least one of these through withholding and estimates:
- 90% of your 2026 tax, or
- 100% of your 2025 tax. If your 2025 AGI was over $150,000 ($75,000 married filing separately), that second figure is 110%.
When income arrives late in the year, the annualized income method on Form 2210 Schedule AI can also lower the required early payments.
What is the deadline for 2026 IRA and HSA contributions?
April 15, 2027. IRS Publication 590-A says IRA contributions can be made “by the due date for filing your return for that year, not including extensions.” An extension to October does not buy you more time.
HSA contributions for 2026 have the same April 15, 2027 deadline under IRS Publication 969.
The 2026 limits:
- IRA: $7,500 ($8,600 at 50 or older).
- HSA: $4,400 self-only or $8,750 family, plus $1,000 at 55 or older.
If you contribute between January 1 and April 15, tell the custodian which year the money is for.
SEP IRAs work differently. You can contribute up to the return due date including extensions, so an extended 2026 return gives you until October 15, 2027. See SEP IRA rules.
Which deadlines start with an event instead of a date?
These clocks start the day something happens to you. No calendar will remind you, so they are easy to miss.
| Event | Deadline | If you miss it |
|---|---|---|
| Restricted stock or early exercise | 83(b) within 30 days of transfer | Taxed at each vest instead |
| IRA or plan payout to you | Roll over in 60 days, 1 IRA rollover per 12 months | Taxable, plus 10% if under 59½ |
| Selling at a loss | No identical buy 30 days before or after | Loss disallowed, added to new basis |
| Inherited IRA (death after 2019) | Most non-spouses: empty by end of year 10 | 25% excise tax on shortfall |
| Birth, adoption, or marriage | At least 30 days to add to employer plan | Wait for open enrollment |
| Losing job-based coverage | 60 days to pick a HealthCare.gov plan | Wait for open enrollment |
| Turning 65 | 7-month Medicare enrollment window | Part B up 10% per late year |
| Reaching RMD age | Apr 1 after turning 73 (75 if born 1960+) | 25% excise tax on shortfall |
| Selling your home | Live there 2 of 5 years to exclude $250,000 ($500,000 joint) | More gain taxable |
83(b). The 30 days start at transfer, not vesting. Since July 2025 the IRS has accepted Form 15620 online. How to file an 83(b) election covers the steps.
Rollovers. When a plan pays you directly, the IRS rollover rules require 20% withholding. To roll over the full amount, you have to make up that withheld 20% from other cash within the 60 days.
Inherited IRAs. If the original owner had already reached their required beginning date, final regulations also require annual distributions in years one through nine, per the IRS. Notice 2024-35 applied those rules starting in 2025.
Different rules apply to spouses, minor children, disabled or chronically ill beneficiaries, and anyone no more than 10 years younger than the owner.
Health coverage. The 30-day minimum comes from the HIPAA special enrollment rules in 29 CFR 2590.701-6, and your plan may allow longer. The 60-day Marketplace window is on HealthCare.gov.
Medicare. The initial enrollment period runs from 3 months before the month you turn 65 to 3 months after it. The Part B penalty lasts as long as you have Part B.
If you have coverage through your own or a spouse’s current job, you can qualify for a special enrollment period instead, per Medicare.gov.
RMD age. Under 26 U.S.C. 401(a)(9)(C)(v), the applicable age is 73 for anyone born from 1951 through 1959 and 75 for anyone born in 1960 or later.
Home sales. The tests for the exclusion are in IRS Topic 701.
How Nino tracks life-event deadlines
Nino asks what is changing in your life and keeps your answer in your own words. On each scheduled check, a model reads those words against the day you gave them.
It looks for one of seven events within 12 months of today:
- a wedding
- a new child
- a new job
- a move to another state
- a home sale
- a retirement
- a large stock sale
A plan you only describe as a possibility, or give no timing for, does not count. Anything touching a death, a divorce, an illness, or another loss never produces a card.
When an event matches, Nino quotes it back to you and names the rule and the next step. For example:
- the 30-day window to add a baby to your health plan,
- the per-person 401(k) limit after a job change,
- the safe harbor after a stock sale.
Those rules are fixed text, checked against primary sources such as IRS publications, HealthCare.gov, and Medicare.gov. A second model reviews each card against your situation before you see it.
On Advisor plans, from $3,600 a year, a financial planner and CPAs plan around these dates with you, and federal and state filing is included. Nothing is filed until you approve it. See how the work runs, or book a free consultation if a deadline above applies to you this year.