What is tax-loss harvesting and when should I do it before year-end?

Tax-loss harvesting means selling investments at a loss to offset capital gains realized elsewhere. To count for 2026, the sale must settle by December 31, 2026. The wash-sale rule bars buying a substantially identical security within 30 days before or after the sale. Act before December 2 to avoid the 30-day look-forward window running into 2027.

Year-End Financial Checklist for Families (2026)

Q: What is the 401(k) contribution deadline for 2026?

December 31, 2026 — your last paycheck of the year must include the contribution. You cannot make a lump-sum 2026 401(k) contribution after December 31 the way you can with an IRA. The 2026 limit is $24,500 ($32,500 if age 50–59 or 64+; $35,750 if ages 60–63 via the SECURE 2.0 super catch-up).

Q: Can I still contribute to an IRA for 2026 after December 31?

Yes. IRA and Roth IRA contributions for tax year 2026 can be made up to April 15, 2027 (the tax filing deadline). The 2026 limit is $7,500 per person ($8,600 if age 50 or older). This also applies to HSA contributions.

Q: What is the 2026 HSA family contribution limit?

$8,750 for family HDHP coverage in 2026 (IRS Notice 2026-05). You have until April 15, 2027 to make 2026 HSA contributions, but you must have had HDHP coverage for the months you're contributing for. If you switch plans mid-year, the limit prorates.

Q: When must RMDs be taken in 2026?

December 31, 2026 — unless it is your first RMD year (the year you turn 73 or 75), in which case you can delay the first distribution to April 1, 2027. RMD starting age is 73 for those born 1951–1959 and 75 for those born 1960 or later under SECURE 2.0. Missing an RMD triggers a 25% penalty on the missed amount.

Not financial or tax advice — this is a reference checklist. Your numbers will differ; a fee-only advisor or CPA can model your specific situation.

Two categories of deadlines. December 31, 2026 — hard cutoff for 401(k)/403(b) contributions, HSA and FSA year-end actions, Roth conversions, tax-loss harvesting, RMDs, annual gifting, and charitable giving. April 15, 2027 — softer deadline for IRA, Roth IRA, and HSA contributions (you can still count them toward your 2026 tax year until then). See our 2026 family tax planning guide for the full strategy context.

Contribution Room Calculator

See how much tax-advantaged space your household still has left for 2026. Enter what you've contributed year-to-date.

Earner 1 — age

Earner 1 — 401(k) contributed YTD ($)

Earner 2 — age (leave blank if single earner)

Earner 2 — 401(k) contributed YTD ($)

HSA contributed YTD (family, $)

Marginal federal tax rate

December 31 Hard Deadlines

These items cannot be backdated to 2026 once the calendar flips to 2027.

Year-end planning getting complex?

When 401(k) maxing, Roth conversions, tax-loss harvesting, and 529 gifts all interact, the numbers need to be modeled together — not optimized in isolation. Match with a fee-only family financial advisor who can run the full picture for your household.

April 15, 2027 Deadlines (Still 2026 Tax Year)

These contributions count toward your 2026 taxes even if you make them in early 2027.

IRA or Roth IRA contribution Apr 15, 2027 The 2026 IRA contribution limit is $7,500 per person ($8,600 if age 50 or older — the $1,100 catch-up is now indexed under SECURE 2.0).² Roth IRA phases out at $242,000–$252,000 MFJ. If your income exceeds the phase-out, contribute to a non-deductible traditional IRA and convert it immediately — the backdoor Roth guide explains the mechanics and the pro-rata trap. For families with a non-working or lower-earning spouse, a spousal IRA allows both spouses to contribute even on one income.

HSA contribution to the 2026 limit Apr 15, 2027 If you were enrolled in a qualifying high-deductible health plan in 2026, you have until April 15, 2027 to contribute up to $8,750 (family) or $4,400 (individual).¹ The catch-up for age 55+ is an additional $1,000. If you were enrolled for only part of 2026, use the last-month rule (full-year limit allowed if enrolled on December 1) but you must remain enrolled through the entire following year or pay a penalty. Triple tax advantage: pre-tax contribution, tax-free growth, tax-free medical withdrawals. After age 65, non-medical withdrawals are penalty-free but taxed as ordinary income — making this a stealth IRA. See the HSA strategy guide.

SEP-IRA or Solo 401(k) contribution (self-employed spouse) Apr 15, 2027 If one spouse runs a solo business or freelances, the Solo 401(k) deadline for employee elective deferrals was December 31 — but the employer profit-sharing portion can be contributed up to the tax filing deadline (including extensions, typically October 15, 2027). A Solo 401(k) allows up to $72,000 total in 2026 at the right income level. If you missed the employee deferral deadline and didn't have a Solo 401(k) established by December 31, a SEP-IRA can still be opened and funded up to the April 15 deadline.

Year-End Actions Before You File

Not hard-deadline items, but best completed before January 31 so they inform your return and Q1 planning.

Review W-4 withholding for 2027 Action If you owed a large balance or received a large refund for 2025, recalibrate before January 2027. Dual-earner households are most prone to underwithholding because each employer withholds assuming each income is the only income — the marginal rate is higher on the combined total. Use the W-4 withholding calculator to find the right Step 4(c) additional withholding per paycheck. If you had RSU vesting or ESPP sales in 2026, those are often withheld at 22% but taxed at your actual rate — see the RSU tax planning guide.

Beneficiary audit Action Beneficiary designations on 401(k)s, IRAs, and life insurance policies override your will. A year with a major life event — new child, marriage, divorce, death of a prior beneficiary — makes this critical. Common mistakes: leaving an ex-spouse as beneficiary (very hard to undo posthumously), naming a minor child directly (a court-appointed guardian will manage the funds), and leaving retirement accounts to a trust without confirming it is a see-through trust. See the estate planning guide for beneficiary structure recommendations.

Insurance coverage review Action Year-end is a natural time to confirm your coverage levels before locking in the next year's plan. Items to check: term life insurance coverage amount (did your income or mortgage increase this year?), disability insurance gap versus your actual income (see the disability insurance calculator), umbrella policy limits vs. net worth (the umbrella calculator suggests minimums), and 2027 open enrollment decisions if your employer window is still open. See the dual-income open enrollment guide.

Net worth snapshot Action Take a December 31 net worth snapshot using the family net worth calculator. Tracking this number annually keeps retirement and college savings goals in context — and gives you a clean baseline when you sit down with an advisor. Compare your retirement savings benchmark: 1× income by 30, 3× by 40, 6× by 50 (Fidelity guidelines). If you're behind, the gap informs your 2027 contribution elections.

Frequently Asked Questions

What is the 401(k) contribution deadline for 2026?

December 31, 2026. Your last paycheck must include the contribution — you cannot make a lump-sum 401(k) contribution after year-end the way you can with an IRA. The 2026 limit is $24,500 ($32,500 if age 50–59 or 64+; $35,750 if ages 60–63 via the SECURE 2.0 super catch-up).

Can I still contribute to an IRA for 2026 after December 31?

Yes — IRA and Roth IRA contributions for tax year 2026 can be made up to April 15, 2027. The 2026 limit is $7,500 per person ($8,600 if age 50 or older). HSA contributions for 2026 also have the April 15 deadline.

What is the 2026 HSA family contribution limit?

$8,750 for family HDHP coverage (IRS Notice 2026-05). You have until April 15, 2027 to make 2026 contributions. If you switched plans mid-year, the limit prorates by months enrolled.

How much can I give to a 529 in 2026 without gift tax?

$19,000 per child per parent — or $38,000 per child from a couple — under the 2026 annual gift exclusion. You can also superfund with five years of gifts in one year: $95,000 per child from one parent or $190,000 per child from a couple, using Form 709 to elect pro-ration over 5 years.

When must RMDs be taken in 2026?

By December 31, 2026 — unless it is your very first RMD year, in which case you may delay until April 1, 2027. RMD starting age is 73 for those born 1951–1959 and 75 for born 1960 or later. Missing an RMD triggers a 25% penalty.

What is tax-loss harvesting and when should I act?

Selling positions at a loss to offset capital gains. The sale must settle by December 31. Due to the 30-day wash-sale look-forward, act before December 2 if you want to buy back a similar (not identical) position in December. Losses can offset up to $3,000 of ordinary income ($1,500 MFS) if gains are insufficient.

IRS Rev. Proc. 2025-32: 2026 401(k) deferral $24,500, healthcare FSA $3,400, FSA carryover $680. IRS Newsroom — 401(k) and IRA limits 2026
IRS (2026): IRA contribution limit $7,500; catch-up $1,100 (age 50+) = $8,600 total. IRS Newsroom — IRA limits 2026
IRS Rev. Proc. 2025-32: 2026 LTCG 0% bracket tops at $98,900 MFJ (taxable income). IRS inflation adjustments 2026
SECURE 2.0 Act (2022) §107: RMD age 73 for born 1951–1959; age 75 for born 1960+. IRS Pub. 590-B (2025). IRS Pub. 590-B — RMD rules
IRS Rev. Proc. 2025-32 / IRS FAQ: 2026 annual gift exclusion $19,000 per donee. IRS Gift Tax FAQ

Values verified against 2026 IRS publications and Rev. Proc. 2025-32 as of October 2026.