From 1 July 2027 the 50% CGT discount is replaced by cost-base indexation with a 30% minimum rate on net gains - and gains accrued before that date keep the old 50% treatment (Federal Budget 2026-27). This free calculator models a sale under both systems side by side.
From 1 July 2027, rental losses on established property can no longer offset your wages. They carry forward to offset future rental income, or the eventual capital gain. New builds keep negative gearing. Anything bought before 12 May 2026 is grandfathered on the old rules.
The 50% CGT discount is replaced by cost-base indexation - only your real, inflation-adjusted gain is taxed - with a 30% minimum rate on net gains from 1 July 2027. Gains accrued before that date keep the old 50% discount.
Indexation was Australia's CGT method from 1985 until the Costello reforms in 1999. It's back from 1 July 2027. The idea: only the real gain, after inflation, gets taxed. Buy a property for $600,000. Ten years later, CPI has grown 30 per cent, so the indexed cost base is $780,000. You sell for $1,000,000. Your taxable gain isn't $400,000 - it's $220,000 ($1,000,000 - $780,000).
That $220,000 then falls into your income for the year and is taxed at your marginal rate, with the 30 per cent minimum applying if your effective rate would otherwise be lower. Under the old 50% discount rule, that same gain was halved to $200,000 and taxed at your MTR with no floor. Which is worse depends entirely on how much inflation ate the cost base versus how much your straight-line gain was.
Grandfathered, in a specific sense. If you own a property today, the gain that accrues up to 30 June 2027 is taxed under the old 50% discount when you eventually sell. The gain from 1 July 2027 onwards falls under the new indexation and 30% minimum. Your accountant will apportion by hold days on either side of the switchover.
Selling before 1 July 2027 keeps the entire gain under the old rules. Holding through the switchover means each year afterwards adds a slice of gain that gets the new treatment. For long holders with big embedded gains, that's a meaningful reason to look at the numbers now rather than in 2029.
The 30% minimum applies to the effective tax rate on your net capital gain, not to your marginal rate as a whole. If indexation reduces your taxable gain to a small number and your other income sits you at (say) 15%, the floor lifts the CGT portion to 30%. If you're already on the 37% or 45% bracket, you're above the floor and it does nothing.
The design intent is to stop the strategy of taking a big gain in an otherwise-low-income year to sit under a low bracket. It doesn't stop strategies of long holds or investing through structures - those still work.
For most investors with an accrued gain and a normal marginal rate, selling before 30 June 2027 gives the cleanest outcome: the whole gain gets the old 50% discount, no apportionment, no 30% floor. If you were planning to sell in the next two years anyway, bringing it forward is worth pricing.
For long holders who aren't planning to sell for another decade, the answer changes - you'd be crystallising a tax bill early to escape a regime that might only touch a slice of your total gain. Inflation, the accrual date, and your future income year all matter. Run both dates through the calculator and see what your actual after-tax number is.
Our interpretation of announced measures, not final law and not advice - confirm with your accountant.