Capital Gains 66.7% Inclusion & Alternative Minimum Tax (AMT)

The Structural Shift in Canadian Capital Gains

For more than two decades, Canadian investors operated under a stable tax regime: exactly 50% of all net capital gains were included in taxable income. That baseline changed fundamentally with the federal implementation of the two-tier capital gains inclusion regime alongside the sweeping overhaul of the Alternative Minimum Tax (Bill C-59) under Section 127.5 of the Income Tax Act.

These dual legislative changes dramatically increase the effective tax rate on high-value asset liquidations, including the sale of secondary real estate (family cottages, rental properties), concentrated stock portfolios, corporate retained earnings, and privately held business shares.

In top tax bracket provinces like Ontario (53.53% marginal rate), the top effective tax rate on capital gains jumps from 26.76% to 35.69%—an immediate 33.3% relative tax increase on capital gains exceeding $250,000.

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The Blow to Corporate Holding Companies (CDA Compression)

For incorporated professionals and business owners, the impact is doubly severe. Corporations do not receive the $250,000 lower inclusion threshold. Every single dollar of corporate capital gain is subject to the 66.67% inclusion rate.

Crucially, this shrinks the Capital Dividend Account (CDA):

• Under the 50% Rule: A $300,000 corporate capital gain generated $150,000 in taxable corporate income and $150,000 into the CDA, which could be distributed to shareholders completely tax-free.
• Under the 66.67% Rule: The same $300,000 capital gain results in $200,000 in taxable corporate income and only $100,000 into the CDA. The tax-free cash available to pull out of the corporation drops by one-third!

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The Overhauled Alternative Minimum Tax (Bill C-59 / ITA 127.5)

Even if an individual’s regular tax liability appears manageable, the federal Alternative Minimum Tax (AMT) under Section 127.5 can trigger an unexpected secondary tax bill. AMT runs a parallel tax calculation with fewer deductions and a flat statutory rate, requiring you to pay whichever calculation is higher.

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Tactical Defenses: Spreading Gains & The 5-Year Reserve Election

To defend against the 66.7% inclusion bracket and AMT, sophisticated investors deploy three primary structures:

1. The Capital Gains Reserve Election (ITA Section 40(1)(a)(iii))

When selling real estate (such as a cottage or rental building) or private business shares, you are not required to take 100% of the purchase price in cash at closing. If you accept a vendor take-back (VTB) mortgage or promissory note payable over time, you can elect a Capital Gains Reserve under ITA Section 40(1)(a)(iii).

The reserve allows you to spread the capital gain across up to 5 taxation years (recognizing a minimum of 20% of the gain each year):

2. Spousal Stacking on Jointly Owned Assets

Because the $250,000 annual threshold applies per individual, co-owning secondary properties or investment portfolios with your spouse doubles your family’s 50% inclusion ceiling to $500,000 per calendar year. When selling jointly titled assets, the gain is split 50/50, keeping up to $500,000 of family capital gains within the 50% tier.

3. Lifetime Capital Gains Exemption (LCGE) Structuring

For entrepreneurs and business owners selling shares of a Qualified Small Business Corporation (QSBC), the Lifetime Capital Gains Exemption increased to $1,250,000 (indexed to inflation). Capital gains covered by the LCGE are 100% exempt from regular capital gains tax, though proper structuring is necessary to mitigate AMT recapture.

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Interactive Calculator: Capital Gains Inclusion & AMT Exposure Engine

Model a major capital gain below to compare the tax impact under 50% vs. 66.7% rules, quantify the multi-year reserve tax savings, and test your AMT exposure.

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Case Study: Selling the Family Vacation Cottage ($650,000 Gain)

Scenario: Claire and her late husband acquired a Muskoka cottage in 1998 for $150,000 (adjusted cost base). Today, Claire sells the property for $800,000, triggering a $650,000 capital gain. Claire already uses her principal residence exemption on her primary home in Toronto.

Path A: Full Cash Closing in a Single Calendar Year

• First $250,000 of gain is included at 50%: $125,000.
• Remaining $400,000 of gain is included at 66.67%: $266,667.
• Total taxable capital gain added to Line 12700: $391,667.
• At Ontario’s top 53.53% marginal tax bracket, Claire pays $209,659 in capital gains tax.

Path B: Structuring a 5-Year Vendor Take-Back (VTB) Note Under ITA 40(1)(a)(iii)

• Claire receives $200,000 cash at closing and accepts a 5-year secured VTB mortgage from the buyer for the remainder at a 6% market interest rate.
• Claire files Form T2017 electing the Capital Gains Reserve, recognizing exactly $130,000 of capital gain per year for 5 years.
• Because each year’s gain ($130,000) is well below the $250,000 threshold, 100% of the gain is included at the lower 50% rate ($65,000 taxable per year).
• Total taxable capital gain over 5 years is only $325,000 (saving $66,667 in taxable income).
• Claire’s total tax bill drops to $173,972, saving an immediate $35,687 in taxes while earning $75,000+ in interest income on the secured VTB note!

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Step-by-Step Capital Gains Defense Checklist