15-minute tax moves you can do today

By Tom, CPA · Updated October 27, 2026

Part of: Easy Tax Strategies

TL;DR: Five quick tasks, each under 15 minutes: bump your 401(k) percentage, start HSA contributions, switch your brokerage to specific-lot identification, request an IRS Identity Protection PIN, and run the withholding estimator. Together they can save real money and prevent tax-season disasters.

Educational only, not tax, legal, or investment advice. Examples are illustrations, not predictions. Rules and limits change; verify current figures and talk to a qualified professional about your situation.

You have 15 minutes. You could watch a video of someone pressure-washing a driveway, or you could do something your future self will actually thank you for. This checklist is for the second option. Each move is small, mainstream and documented by the IRS. None of them need an appointment.

Figures are 2026 IRS amounts, checked October 27, 2026. For the bigger picture, see easy tax strategies ranked by effort.

CPA Warning Label: Fifteen minutes to set up, a full year of consequences: double-check contribution limits so a quick change does not become an excess contribution.

Raise 401k %

Time: 5 minutes. Where: your plan's website or HR portal.

• Log in and find "contribution rate" or "deferral election."
• Raise it by at least 1 percentage point, or enough to capture the full employer match.
• Look for an auto-increase feature and set it to add 1% a year.
• Check the 2026 cap: $24,500, plus $8,000 if you are 50 or older ($11,250 at ages 60 to 63).

A 1% bump on a $70,000 salary is $700 a year. In the 22% bracket that saves $154 of federal income tax, so take-home pay falls by only about $546, or $21 per biweekly check. More in the 1% raise trick.

Open HSA

Time: 10 to 15 minutes, if you are eligible.

• Confirm you are on an HSA-eligible plan. For 2026, that means a deductible of at least $1,700 self-only or $3,400 family, or a bronze or catastrophic marketplace plan, which are now treated as HSA-compatible.
• No other disqualifying coverage (a general-purpose health FSA, Medicare, or a spouse's non-HDHP family plan covering you).
• Start payroll contributions if your employer offers them; otherwise open an HSA with a provider and contribute directly.
• 2026 limits: $4,400 self-only, $8,750 family, plus $1,000 at 55+.

Step-by-step: open and fund an HSA in 20 minutes.

Lot method

Time: 3 minutes. Where: brokerage account settings, often under "cost basis" or "tax lot."

When you sell part of a position, the lot method decides which shares are sold and therefore how much gain you report. First-in, first-out typically sells your oldest, lowest-cost shares, maximizing gain in a rising market. Specific identification lets you pick high-cost lots, or lots with losses, at sale time. Many brokerages also offer automated variants such as "highest cost" or "tax-efficient loss harvester."

Two cautions: for mutual funds, average cost is common and changing away from it has rules; and the choice has to be made by the time of the sale, not after.

IP PIN

Time: 10 minutes. Where: irs.gov, Get an IP PIN.

An Identity Protection PIN is a six-digit number known only to you and the IRS. A return filed with your Social Security number but without the correct IP PIN gets rejected, which shuts down the most common refund-fraud scheme. Anyone who can verify their identity can opt in. A new PIN is issued each year; your tax software will ask for it.

Check W-4

Time: 10 minutes. Where: IRS Tax Withholding Estimator, then your payroll portal.

• Grab your most recent pay stub (and your spouse's).
• Enter year-to-date pay and withholding into the estimator, which the IRS updated for the 2025 law changes.
• If it shows a big refund or a big balance due, submit a new Form W-4 with the suggested adjustment.

Two-earner couples are the classic under-withholding case; see tax moves for couples and the 10-minute withholding checkup.

Worked example: one coffee break

Illustration: A single worker earns $70,000 in 2026 and takes the standard deduction. Taxable income: $70,000 − $16,100 = $53,900, which is $3,500 above the start of the 22% bracket ($50,400).

In one 15-minute session she raises her 401(k) by 2% ($1,400 a year) and starts HSA payroll contributions of $100 per paycheck over 26 paychecks ($2,600). Total pre-tax: $4,000. New taxable income: $49,900.

That is about $69 of annual savings per minute of effort. Note the bracket edge: once taxable income dips below $50,400, each further dollar saves 12%, not 22%. Always check where the line is.

What to do after the 15 minutes

Put three reminders on your calendar, because the quick moves only stay quick if you revisit them:

1. Open enrollment: re-elect HSA and FSA amounts; elections usually do not roll over automatically for FSAs.
2. Early December: look at realized gains and losses in taxable accounts and decide on loss harvesting before December 31.
3. March: decide on any prior-year IRA or HSA contribution before the April deadline, and enter your new IP PIN when you file.

And if you change jobs mid-year, recheck your 401(k) total: the $24,500 deferral limit is per person across all employers, and plans at two employers cannot see each other. Excess deferrals must be withdrawn by the following April 15 to avoid double taxation.

Bonus 15-minute moves

• Update beneficiaries on your 401(k), IRA and HSA. Not a tax saving today, but a bad beneficiary form can cost heirs years of tax deferral.
• Turn on dividend reinvestment carefully in taxable accounts if you plan to harvest losses; automatic reinvestment within 30 days can trigger a partial wash sale.
• Download last year's return and IRS account transcript so you have them before you need them.