The Vesting Calendar You Did Not Set

What actually happens on a vest date

A restricted stock unit is a promise to deliver shares once conditions are met. On the day those conditions are satisfied, the shares are delivered and their full market value becomes ordinary compensation income, reported on your W-2, taxed at your marginal rate.

This happens whether or not you sell. It happens whether or not you wanted the shares that day. It happens on a date chosen when the grant was written, frequently years earlier, by somebody optimizing for retention rather than for your tax year.

Your employer then withholds, usually by retaining a portion of the shares. The rate applied is a statutory default for supplemental wages, not a calculation of what you owe. At high incomes that distinction is worth a great deal of money.

The withholding gap

Supplemental wages, which is what a vest is, carry a flat statutory withholding rate of twenty-two percent on the first million dollars of such wages in a calendar year, and thirty-seven percent above that.

If your marginal rate is well above twenty-two percent, and at $2M of income it is, then everything withheld in that first tranche is withheld at materially less than you owe. Nobody has made an error. The employer applied the rate the regulations specify. The shortfall is simply yours to discover.

The mechanism for avoiding the penalty is the estimated tax safe harbor, which generally requires paying in either ninety percent of the current year's liability or, for higher earners, a hundred and ten percent of the prior year's. Both require someone to have looked at the number during the year rather than after it. Neither happens automatically.

What is decided for you, and what is not

It is worth being precise about the boundary, because a good deal of anxiety in this area attaches to things that genuinely cannot be changed, while genuinely available levers go unused.

The right-hand column is the whole of the planning surface, and everything in it has to be arranged in advance. Once the vest has occurred, the income is fixed and only the disposition decisions remain.

The multi-year problem nobody owns

Grants accumulate. An executive several years into a tenure typically holds overlapping awards, each vesting on its own schedule, granted by different compensation committees in different years for different reasons.

Nobody is looking at the aggregate. Your employer administers each grant according to its terms. Your preparer reports what happened after the year ends. The consequence is that two large tranches landing in the same calendar year, which is a materially worse outcome than the same two tranches split across two years, happens by accident rather than by decision.

Where the timing genuinely cannot be moved, and often it cannot, the response is to arrange the rest of the picture around it: to know two or three years ahead which years will spike, and to have the offsetting side of the ledger positioned for those years specifically rather than assembled hurriedly in December.

The position you did not choose to build

There is a second consequence of vesting that has nothing to do with tax. Every vest that is not sold increases your holding in a single company, and that company is also your employer.

Most people describe this as being well diversified because they also hold index funds. They are not. If the business has a difficult year, the shares fall and the security of the job weakens in the same quarter. The concentration is not offset by the salary. It is compounded by it.

The usual reason for not addressing it is that selling triggers a consequence. That reasoning is understandable and it gets more expensive every year it is applied, because the position keeps growing relative to everything else. Reducing concentration deliberately and in stages is a far better outcome than reducing it in one transaction, and both are better than having it reduced for you by a drawdown.

Where this lands

1. 01Map the next thirty-six months of vesting now. Not this year's. All of it, across every grant, on one page. Most people have never seen this view and find it clarifying.
2. 02Check the withholding on your most recent vest against your actual marginal rate. If the gap is material, the fix is an estimated payment or additional withholding during the year, not a larger check in April.
3. 03Identify which of the next three years spike, and treat those as planning years. Offsetting deductions and credits need to be planned before the spike, not after it.
4. 04Decide a concentration policy in advance. A rule set in a calm quarter, such as a target holding or a standing disposition schedule, is far easier to follow than a decision made after a move in the share price.
5. 05If a liquidity event is anticipated, start considerably earlier than feels necessary. Double-trigger grants vest on the event, which means the largest income year of your life may arrive inside a blackout with very little notice.

None of this is exotic. It is ordinary, unglamorous sequencing, and it is neglected mainly because no one party to your financial life has been asked to own it.