The ETS covers all emissions of the country's economy excluding agriculture.
It was last ammended in 2020. According to the CAT, "the reform introduces a cap to limit the emissions covered by the ETS, which will decline in accordance with New Zealand’s carbon budgets based on emissions targets (Ministry for the Environment, 2020c). The government set a provisional carbon budget for 2021 to 2025, in lieu of the carbon budget developed by the Climate Change Commission released in 2021 which the government is yet to consider."
From 2025 on, the ETS will include emissions from agriculture.