AMT in Canada 2026: Who Pays the Alternative Minimum Tax and When

The Alternative Minimum Tax is a parallel federal tax calculation that makes sure people with large deductions or heavily-sheltered income still pay a minimum amount of tax. Since the overhauled rules took effect on January 1, 2024, it applies a flat 20.5% rate to a broadened income base, counts 100% of capital gains instead of 50%, and allows only 80% of most non-refundable credits. If that parallel calculation comes out higher than your regular federal tax, you pay the difference — and those expanded rules remain fully in force for the 2026 tax year.

For the vast majority of Canadians, the AMT is a rule that never touches their return. The Department of Finance estimated when it introduced the reform in Budget 2023 that roughly 99% of the AMT collected under the new regime would come from taxpayers earning more than $300,000, with the number of Canadians paying it expected to drop while the amount collected rose. That is the design: fewer people, larger bills, concentrated at the top.

What the Alternative Minimum Tax Actually Is

Think of the AMT as a floor rather than a separate tax. The regular income tax system deliberately allows a wide range of deductions and preferential rates — the 50% capital gains inclusion rate, the lifetime capital gains exemption on qualified small business shares and farm property, employee stock option deductions, resource and flow-through share write-offs. Each exists for a policy reason. Stacked together in a single year, though, they can bring a very large income down to a very small tax bill.

The AMT recalculates your income with many of those preferences reduced or removed, subtracts a generous exemption, and applies one flat rate. You pay whichever number is higher — regular tax or AMT. The Canada Revenue Agency handles the whole calculation on Form T691, Alternative Minimum Tax, and Ontario runs its own parallel provincial minimum tax on Form ON428 that is calculated as a percentage of the federal AMT.

The current rules came out of the 2023 federal budget and took effect January 1, 2024. Before that, the rate was 15% and the exemption was only $40,000. The reform raised the rate to 20.5%, lifted the exemption to $173,205 — indexed to inflation each year since — and broadened what goes into the calculation. It also narrowed the field: because the exemption is now roughly four times higher, middle-income Canadians who might once have brushed against the AMT no longer do.

Who Gets Caught in 2026

The AMT is triggered by the character of your income, not just its size. In 2026, exposure is most likely if you:

• Realized a large capital gain. The AMT includes 100% of capital gains versus 50% in the regular system. This is by far the most common trigger in Ontario — a rental property, a cottage, a cabin on Lake Huron, or a long-held non-registered portfolio sold in one go.
• Claimed the lifetime capital gains exemption. Selling qualified small business corporation shares or qualified farm property uses an exemption that the 2025 federal legislation raised to $1.25 million. The AMT adds back 30% of the claimed exemption.
• Exercised employee stock options. The stock option deduction is reduced to 30% inclusion for AMT purposes.
• Donated appreciated securities. The capital gain on a donation of publicly listed securities is fully exempt in the regular system; the AMT brings 30% of it back in.
• Claimed large non-refundable credits. Only 80% of most credits, including the charitable donation credit, can be applied against AMT.
• Used flow-through shares, limited partnership losses, or certain tax shelters.

Notably, some income sources common in London-area retirements do not trigger AMT on their own. Ordinary RRIF minimum withdrawals, CPP, OAS, and defined benefit pension income are fully taxable already, so there is no preference for the AMT to strip away. Statistics Canada reports that the median after-tax income of Canadian senior families was approximately $75,000 in 2023 — comfortably below the AMT exemption, which is one reason this rule is largely irrelevant to a typical retirement income plan. The exception is the year a major asset changes hands.

"The AMT almost never shows up in a normal retirement year. It shows up in the one year somebody sells the cottage or the rental duplex — and by then the transaction is done and the options are gone. That's why we run the numbers before the sale, not at tax time." — Marc Pineault, retirement planner in London, Ontario

A Worked Example: Selling a London Rental Property

Numbers make this concrete. Consider a hypothetical Ontario couple — call them the Mercers — who hold a $1.4 million portfolio of registered and non-registered assets plus a rental duplex near Old East Village that they bought years ago. They sell the duplex in 2026 for $780,000 with an adjusted cost base of $320,000.

Step 1 — The gain. $780,000 − $320,000 = $460,000 capital gain, split 50/50 between them, so $230,000 each.

Step 2 — Regular tax base. Under the regular system, half is taxable: $230,000 × 50% = $115,000 added to each spouse's taxable income. On top of, say, $45,000 of pension and RRIF income, that puts each of them at roughly $160,000 of regular taxable income.

Step 3 — AMT base. The AMT counts the whole gain: $230,000 × 100% = $230,000 each. Added to the same $45,000 of other income, the adjusted taxable income for AMT is about $275,000 each.

Step 4 — Subtract the exemption. Roughly $185,000 for 2026 after indexation: $275,000 − $185,000 = $90,000.

Step 5 — Apply 20.5%. $90,000 × 20.5% ≈ $18,450 federal AMT, before credits — and only 80% of the basic personal amount and other non-refundable credits can be applied against it.

Step 6 — Compare. Federal regular tax on roughly $160,000 of taxable income works out to something in the mid-$28,000s after the basic personal amount. Because the regular figure exceeds the AMT figure, no AMT is payable in this example.

That result is the point worth absorbing: a $460,000 gain in a single year is a large event, and it still did not generate AMT, because a fully taxable capital gain also generates a lot of regular tax. The AMT bites when the gain is accompanied by something that suppresses the regular tax — a lifetime capital gains exemption claim, a stock option deduction, or a very large donation credit. Change the example so the duplex is instead qualified farm property sheltered by the $1.25 million lifetime exemption, and the regular tax collapses toward zero while the AMT base stays high. That is when the parallel calculation takes over.

How the Calculation Runs, Step by Step

1. Start with your regular taxable income.
2. Add back the preferences: 100% of capital gains instead of 50%, 30% of any lifetime capital gains exemption claimed, 30% of the stock option deduction, 30% of the capital gain on donated securities, and most flow-through share and limited partnership deductions.
3. Allow only 50% of certain deductions — including employment expenses, moving expenses, interest and carrying charges on investment loans, and the northern residents deduction.
4. Subtract the basic exemption, indexed annually from the 2024 base of $173,205.
5. Multiply the remainder by 20.5% to get gross federal AMT.
6. Subtract 80% of your allowable non-refundable tax credits.
7. Compare to your regular federal tax. Pay the higher of the two.
8. Ontario calculates its own minimum tax on ON428 as a percentage of the federal amount, so the provincial layer moves with the federal one.

The Bank of Canada's inflation figures matter here in a quiet way: because the exemption is indexed to CPI, every year of inflation lifts the threshold. With CPI inflation running near the Bank of Canada's 2% target midpoint through 2025, the exemption has climbed roughly $12,000 from its 2024 starting point — a small but real widening of the safe zone.

Getting the AMT Back

This is the most overlooked feature of the rule. AMT you pay above your regular federal tax is not lost. It becomes a carryforward credit available for the next seven tax years, usable in any year where your regular tax exceeds your AMT for that year.

For a retired household in Ontario, that recovery window is often quite workable. If a large gain in 2026 creates AMT, and 2027 through 2033 are ordinary years of RRIF withdrawals and pension income with no preferences at all, regular tax will exceed AMT in each of them and the credit draws down steadily. The practical risk is the opposite pattern: very low income in the following years, which leaves little regular tax to absorb the credit before it expires. The CRA's income tax page sets out the filing mechanics, but the planning question — will I have enough regular tax in the next seven years to use this? — is one worth answering before the triggering transaction, not after.

Where AMT Meets the Rest of a Retirement Plan

The AMT rarely travels alone. The same year that produces a large capital gain also produces the highest net income of someone's retirement, which means it interacts with several other decisions at once.

OAS recovery tax. A $230,000 gain pushes net income far past the OAS clawback threshold, and the 15% recovery tax on income above roughly $93,000 can cost the full annual benefit. The OAS clawback strategy guide walks through how one-time income events interact with that threshold.

RRSP and RRIF sequencing. A high-income year is usually the wrong year to accelerate registered withdrawals, and a low-income year afterward may be the right one. The RRSP meltdown guide covers how the years between retirement and age 71 can be used deliberately, while the RRIF withdrawal strategy guide explains how minimum withdrawals interact with a lumpy income year.

Staging the transaction. Where a sale can be structured across two calendar years, or a donation split across two, the AMT base in each year falls. Whether that is possible depends entirely on the asset and the buyer. Marc Pineault's practice in London, Ontario often models these sequences side by side before a client signs anything, and the free retirement planning calculators on this site let you sketch the income picture in each year yourself.

Planning Before the Event, Not After

The AMT is invisible until a return is filed, which is exactly why it surprises people. With the expanded rules now in their third full year, the pattern is consistent: the households that get caught are the ones where a large deduction or exemption sits beside a large gain in the same twelve months.

If a property sale, business transition, structured donation, or stock option exercise is on the horizon, the useful work happens in the months before the transaction — modelling the AMT base, checking whether the exemption absorbs it, and confirming that the following seven years can realistically absorb any carryforward credit. Marc Pineault is a retirement planner based in London, Ontario who works with households navigating exactly these one-time events alongside their broader retirement income picture. If you would like to review how the AMT might fit into your own tax picture this year, book a consultation.