Executive Compensation Tax Planning Calendar: What to Do and When

Most executives experience tax season as a surprise — a large April bill that reflects decisions (or missed decisions) from the prior year. It doesn't have to be that way. Executive compensation is unusually time-sensitive: NQDC elections have statutory deadlines, ISO exercises have optimal quarters, 10b5-1 windows open and close around earnings, and RSU vests create withholding gaps that compound through the year.

This calendar maps the natural rhythm of executive compensation decisions against the tax calendar. It won't eliminate complexity, but it surfaces the moments when action is cheapest and inaction is most costly.

January–March: Reconstruct and calibrate

January: Read your W-2 carefully

Your W-2 is the most data-dense document you'll receive about your compensation. For executives, the standard wage boxes often hide significant complexity:

• Box 12, Code V: The ordinary income recognized on NQO (NSO) exercises. If this is large, verify that your basis in those shares is documented in your brokerage account — brokers historically under-reported basis on NQO shares, and you may have overpaid taxes in prior years.
• Box 12, Code AA/BB: Roth 401(k) and Roth 403(b) contributions — verify amounts if you participate.
• Box 14: Employer-reported items that may include NQDC distributions, state disability insurance, or memo items. Read every entry.
• Box 1 vs. Box 3 gap: The Social Security wage base is $184,500 in 2026.¹ A large gap between Box 1 and Box 3 can indicate NQDC deferrals (which reduce FICA when deferred), large NQDC distributions hitting Box 1 only, or compensation deferred past the FICA wage base. Understand why the boxes differ.

January–February: File 83(b) elections (30-day clock runs year-round)

If you received unvested restricted stock, early-exercised options, or a profits interest grant in the past 30 days, the 83(b) election clock is running right now — regardless of the time of year. There is no seasonal pattern to when private companies issue grants. Miss the 30-day window and the election is permanently invalid.²

See the Section 83(b) Election guide for filing mechanics and how this interacts with ISO early exercise and QSBS.

March–April: Q4 balance due and Q1 estimated tax

April 15 carries two obligations for most executives: any remaining balance on the prior year's return, and the first quarter estimated tax payment for the current year. Executives with significant RSU vests, NQO exercises, or NQDC distributions often have underwithholding from W-2 sources — the supplemental rate is 22% but marginal rates are 35–37% federal plus state.

If your April 15 payment is large enough to feel punishing, that's diagnostic information: your withholding strategy for the rest of the year needs adjustment. Options include increasing W-4 withholding, making larger quarterly estimates, or restructuring when income events occur.

Use the RSU Tax Withholding Estimator to model the shortfall if RSU vests are a primary driver.

April–June: ISO exercise season

April: Update your annual tax projection

After filing (or extending) your return, you have the most complete picture of last year's income, AMT position, and credits. Use this as the baseline for this year's projections. Key questions:

• Did you generate AMT credit last year that can be utilized this year? If so, model the optimal ISO exercise amount that uses the credit while staying below AMT liability for 2026.
• What are your RSU vesting events for the rest of this year? Estimate each one's ordinary income impact and withholding.
• If you have a 10b5-1 plan with scheduled sells, what gain or loss will each tranche trigger, and in what bracket?

April–May: The first 10b5-1 trading window

For executives subject to quarterly blackout periods, the window typically opens 2–3 days after the Q4/annual earnings release and closes several weeks before the next report date. This is usually the longest open window of the year — the Q1 window that follows the annual earnings release and runs until roughly six weeks before Q1 earnings.

Shares sold via 10b5-1 during this window execute per the plan schedule. If you don't have a 10b5-1 plan, the Q4 annual earnings open period is also the time most insiders can amend or adopt a new plan — though the 90-day cooling-off period (for officers and directors) means trades under a new plan can't begin until summer.³

See 10b5-1 Plans for Executives for SEC rule requirements.

May–June: ISO exercise modeling

For executives with ISOs at private or public companies, Q2 is often the optimal exercise quarter — after the prior-year return is filed (giving you a clean AMT starting point), before summer blackout periods, and with maximum time remaining in the year to see how income develops.

The ISO AMT calculation depends on your year-to-date income, projected year-end income, and the ISO spread at current FMV. A $200K ISO exercise in June with $450K of other income puts you in a different AMT position than the same exercise in November with $800K of other income. The order matters; plan it in April when you have visibility.

See ISO Stock Options and the AMT for the mechanics, including the 2026 exemption amounts.

June 15: Q2 estimated tax due

By June you should have better visibility into the year's income. If you've had an unexpectedly large income event — a large RSU vest, a bonus significantly above plan, a 10b5-1 tranche that executed — adjust your Q2 estimated payment upward to avoid underpayment penalties.

July–September: Concentrated stock and advance planning

July–August: Summer 10b5-1 window

The summer trading window typically follows Q2 earnings and is often shorter than the Q1 window. For executives with scheduled 10b5-1 sells, this window will execute automatically. Use the proceeds and gain realization to update your full-year tax projection.

If you have a concentrated position you're trying to reduce outside of a 10b5-1 plan, and you're not subject to insider trading restrictions on that security, summer is typically a reasonable time to begin a gradual sell-down program.

August–September: Begin NQDC election analysis

NQDC deferral elections for 2027 must be made before December 31, 2026 — and most plan documents require submission by December 15 or earlier.⁴ The analysis takes time: you need to model your expected income in the distribution years, compare expected rates at deferral versus distribution, assess the employer's credit risk, and choose a distribution trigger and schedule.

Starting in August or September gives you time to:

• Project your 2026 income accurately enough to forecast deferred compensation amounts
• Model distribution scenarios for various retirement years and states of residence
• Evaluate whether to elect installment distributions (spreading income over 5–10 years to avoid bracket concentration) or a lump sum (appropriate if you expect to move to a no-income-tax state at retirement)

Use the NQDC Deferral Calculator to model the tradeoffs. See the NQDC Strategy Guide for the full framework including the six 409A distribution triggers and re-deferral rules.

September 15: Q3 estimated tax due

September 15 is the last estimated payment before year-end. By now you have 9 months of income data. If your projected liability is significantly above what you've paid year-to-date, this is the last easy opportunity to make a large catch-up payment without accruing underpayment interest for Q4.

September: Pending M&A — request 280G analysis now

If your company is in acquisition discussions — even if not publicly announced — request a 280G analysis before any deal announcement that becomes material nonpublic information. Once an announcement is made, certain advisory conversations become constrained. The analysis is most useful while you can still potentially restructure golden parachute provisions or a severance agreement.

The 280G excise tax (20% on excess parachute payments, per IRC § 4999) applies when total change-of-control payments exceed 3× your average W-2 compensation over the prior 5 years. See the 280G Parachute Tax Calculator to estimate exposure and model the cutback vs. full-payment scenarios.

October–December: The election window — most consequential period

October–November: Q3 earnings window + 10b5-1 execution

The Q3 trading window is often narrow — Q3 earnings typically release in October, and Q4 pre-announcement quiet periods begin in November. For 10b5-1 plan holders, this window executes per schedule. For executives without a 10b5-1 plan, check your insider trading policy carefully: year-end is when concentrated stock decisions are most costly to defer.

By December 15: NQDC deferral election deadline

This is the most consequential soft deadline in executive compensation. Under IRC § 409A, the election must be made before the start of the year in which compensation will be earned — statutory deadline December 31, but most plan administrators require submission by December 15.⁴ Missing it means you cannot defer any additional amount for the upcoming year.

November–December: Final ISO exercise window

December is your last chance to use the remaining AMT-safe zone for the current year. By November you know your actual income: W-2 wages, RSU vests, and NQDC distributions. The unknown is how much ISO bargain element you can add before AMT exceeds regular tax. Model this calculation in November for any exercise you want to include in the current tax year.

Key coordination trap: if you receive a December bonus (common for fiscal-year companies), add the bonus to your income projection before calculating ISO exercise room. A $200K bonus that posts December 31 can push you into a higher AMT position than your November calculation assumed.

December 31: Hard year-end deadlines

December: Year-end RSU vest — withholding check

Many companies have a December RSU vest scheduled as part of annual grant cycles. If your company withholds shares at the 22% supplemental rate and your actual marginal rate is 35–37% federal plus state, a large December vest can create a significant underpayment. Unlike wages, the RSU withholding shortfall doesn't get corrected by your W-4 — it shows up as a balance due in April.

After a large December vest, estimate whether you need to make an additional Q4 estimated payment by January 15 to cover the shortfall.

Interactions that require coordinated planning

These decisions look independent but are actually coupled. Getting one right while ignoring the other can cost more than the savings from the first.

NQDC election year ↔ ISO exercise year

A year with large NQDC deferral reduces current income (favorable for AMT headroom, good for ISO exercises). But a large NQDC distribution year — when past deferrals are paid out — spikes ordinary income, leaving little room for ISO exercises in the same year. Coordinate NQDC distribution schedules with planned ISO exercise years years before the events occur.

RSU vest ↔ ISO exercise

Both events add to income in the year they occur. RSU vests create ordinary income; ISO exercises add to AMTI. A year with $1M in RSU vests is a year with less ISO AMT headroom. Plan exercise tranches with vest schedules in view.

10b5-1 trading ↔ loss harvesting

Executives who sell employer shares via a 10b5-1 plan and also hold the same security outside the plan should be careful about loss harvesting. Selling other lots of the same security at a loss within 30 days before or after a 10b5-1 plan sale can trigger the wash-sale rule if the 10b5-1 purchase is of a "substantially identical" security. Consult your plan's terms and a tax advisor before harvesting losses on securities in an active 10b5-1 plan.

Change-of-control ↔ NQDC election

A change of control is one of the six IRC § 409A permitted distribution triggers. If your company is acquired before the end of the year, previously elected deferral schedules may be overridden by a 409A-compliant CoC distribution. This can move a large NQDC balance into income in the acquisition year — which may also be the year with a large 280G parachute payment. The combined tax in a CoC year can be extraordinary; see Executive Equity at Acquisition.

1. IRS Rev. Proc. 2025-32 — 2026 Social Security wage base: $184,500. IRS 2026 inflation adjustments announcement.
2. Treas. Reg. § 1.83-2 — 83(b) election procedure, 30-day deadline from date of transfer, and no extensions. law.cornell.edu/cfr/text/26/1.83-2.
3. SEC Rule 10b5-1(c)(1)(ii)(B) — 90-day cooling-off period for officers and directors of issuers adopting new 10b5-1 plans (or 120 days to next scheduled trade, whichever is longer). Adopted in final rules effective Feb. 27, 2023. SEC Release 33-11138.
4. IRC § 409A(a)(4)(B) and Treas. Reg. § 1.409A-2(a)(3) — NQDC deferral elections must be made not later than the close of the preceding taxable year. IRS Notice 2005-1 Q&A-9 clarifies plan administrator flexibility to set earlier internal deadlines. law.cornell.edu/uscode/text/26/409A.
5. IRS Rev. Proc. 2025-32 — 2026 401(k) elective deferral limit: $24,500; age 50+ catch-up: $8,000 (total $32,500); ages 60–63 super catch-up: $11,250 (total $35,750) per SECURE 2.0 § 109. IRS 2026 inflation adjustments.
6. IRS Rev. Proc. 2025-32 — 2026 HSA contribution limits: $4,400 self-only / $8,750 family; minimum HDHP deductible: $1,650 / $3,300; out-of-pocket maximum: $8,300 / $16,600. IRS 2026 inflation adjustments.

Contribution limits per IRS Rev. Proc. 2025-32. NQDC election deadline rules per IRC § 409A and Treas. Reg. § 1.409A-2. 10b5-1 cooling-off rules per SEC final rule effective February 2023. Values verified April 2026.