In September, the wealth manager rebalanced the portfolio. An equity position had grown to 34% of the taxable account, above the target allocation. They trimmed it back to 28%. The transaction was routine. The documentation went to the custodian.
The gain was $48,000. It landed on the year-end 1099 in February.
Elsewhere in the same portfolio, three positions were sitting at a combined loss of $22,000. They had been sitting there for months. Nobody harvested them because nobody connected them to the September rebalancing. The CPA didn’t know about the $48,000 gain until February. By February, the $22,000 was still untouched, and the year was over.
What rebalancing actually does
A portfolio rebalance in a taxable account is not a paperwork event. It is a series of security sales. Each sale either recognizes a gain or recognizes a loss, depending on what the position cost when it was purchased. When an overweight equity position is trimmed back to target, the shares that are sold generate a taxable event: a long-term or short-term capital gain, depending on how long they were held.
The rebalancing itself is correct. Maintaining target allocations is what a disciplined wealth manager does. The problem is not the rebalance. The problem is that the rebalance creates a tax consequence that has a planning window attached to it, and that window closes on December 31 of the same year.
The window
When the September rebalancing created $48,000 in long-term capital gains, it also created an opportunity. That gain could be partially or fully offset with capital losses from other positions in the portfolio. It could influence Roth conversion sizing: $48,000 of additional gain changes how much bracket room exists before hitting the next tier. It could affect the timing of a charitable gift: a donor-advised fund contribution in the same year as a large capital gain is more tax-efficient than one made in a low-income year.
None of those decisions can be made in February. The charitable gift would have had to be made before December 31. The Roth conversion would have had to be made before December 31. The loss harvest would have had to be executed before December 31.
The window opened in September when the rebalance occurred. It closed in December. The CPA learned about it in February.
Why the CPA doesn’t know
The wealth manager’s rebalancing decision is made inside the portfolio. The custodian records the transactions. The year-end 1099 consolidates them. In February, the CPA receives the 1099 with the annual tax documents.
There is no standard step in this process that routes the rebalancing event to the CPA in September. There is no engagement model that requires the wealth manager to notify the CPA before trimming an overweight position. The two professionals are working from different information sets, on different timelines, without a shared calendar.
The CPA who gets the 1099 in February can report the gain accurately. They cannot offset it, time a deduction against it, or size a conversion around it. That work had to happen before the year closed. The information to do that work had to arrive before December.
The recurring gap
Portfolio rebalancing is not a one-time event. A well-managed portfolio is rebalanced regularly: when allocations drift, when markets move, when contributions are added or distributions are taken. Each rebalancing in a taxable account is a tax event with a planning window. Each window closes at year-end.
In any given year, the wealth manager may have executed four or five rebalancing transactions that generated capital gains. The CPA will see all of them in February. The planning opportunity attached to each one closed before the CPA knew any of them existed.
The rebalancing was right. The tax treatment was correct. The window was real, and it was open for three months. Whether anyone used it depends on whether the CPA knew it was open.
