Adjusted Cost Basis (ACB)

It is a tax figure, not a policy value. The adjusted cost basis does not appear on an illustration beside the cash value and it is not what the contract is worth. It is what the contract has cost the owner for tax purposes, which is a different question.

It moves in two directions at once. Premiums paid increase it. The net cost of pure insurance, a figure prescribed by regulation and rising with the age of the life insured, is deducted from it each year. In the early years premiums dominate and the basis climbs. Later the deduction dominates and the basis falls.

Which is why it declines on a long-held contract. On a policy held for several decades the adjusted cost basis can approach nil, so that almost the whole of any amount withdrawn or surrendered becomes taxable. A household that assumed the tax position of year ten still applied in year thirty has assumed wrongly.

It is the reason two identical contracts produce different tax outcomes. Two policies with the same cash value can carry very different bases depending on how they were funded and how long they have run, and the tax on leaving them differs accordingly.

It is one of the few figures in this subject that improves by being ignored. An owner who never touches the contract never triggers the tax the basis governs, and at death the death benefit is received by a named beneficiary free of income tax regardless of what the basis had fallen to.

Which is why it matters most to people who intend to use the value. A household planning advances against the contract is operating inside a tax rule that moves against them over time, and the year to ask about it is before the first advance rather than after the third.

Ask for the figure rather than estimating it. The insurer holds it, will provide it on request, and no reliable approximation exists from the outside because the deduction each year depends on prescribed mortality figures the owner does not have.

And ask before acting, not after. The tax consequence of an advance, a withdrawal or a surrender is fixed by the basis on the day it happens, and nothing afterwards changes it.

Why it is the least understood figure in the subject

Because it moves invisibly. Nothing an owner receives each year reports it, and the direction of travel reverses partway through the life of the contract without any event marking the change.

Because it is counter-intuitive. Most tax costs rise with what you put in. This one rises, then falls, and on a contract held long enough it approaches nil while the value it governs is at its largest.

And because it only matters at a moment of action. A household that never takes value out never meets it. One that takes value out in year thirty meets it all at once, and the number it meets bears no resemblance to the number that applied when the contract was arranged.

What to do about it

Ask the insurer for the current figure, in writing, before any advance, withdrawal or surrender.

Ask an accountant what the tax would be on the specific amount contemplated, rather than in general. Where a corporation owns the contract, the same figure sets the credit to its Capital Dividend Account, so the question belongs with the accountant who keeps the corporate records.

And model it forward if the contract is intended to be drawn on. The figure is projectable, and a household planning to use the value should know what the tax position looks like in the decade they intend to use it rather than today. A projection of the value itself rests on the dividend scale, which an insurer declares one year at a time and does not guarantee.

There is a habit worth forming around this number, and it takes about a minute a year. When the annual statement arrives, note the adjusted cost basis alongside the cash value, and keep the two figures together in the same place you keep the policy. Ten years of that is a record nobody has to reconstruct later. Without it, the figure has to be rebuilt from premium history and dividend elections going back to issue, and the person doing the rebuilding is usually an executor under time pressure rather than the owner at leisure.

The reason the number moves at all is worth holding onto too. It rises with premiums paid and falls by the net cost of pure insurance, a figure the insurer calculates each year from the amount at risk and the insured's age. As the cash value grows, the amount genuinely at risk shrinks, so the deduction changes over time. That is why a contract twenty years old can carry a basis far below what the owner has paid into it, and why the tax on accessing value can arrive larger than expected. How much can be paid into the contract in the first place is a separate calculation, the exempt test, and the two are regularly confused.