This bill amends the Washington estate tax law by adjusting the applicable exclusion amounts for inflation and establishing new thresholds for estates based on the date of death. The bill reenacts and amends RCW 83.100.020, updating the exclusion amounts to $1,500,000 for decedents dying before January 1, 2006, and $2,000,000 for those dying between January 1, 2006, and January 1, 2014. It introduces new exclusion amounts for subsequent years, including $2,012,000 for 2014, $2,054,000 for 2015, and $2,079,000 for decedents dying between October 1, 2016, and October 22, 2016. The bill continues to increase the exclusion amount annually based on the consumer price index, starting from $2,959,000 for estates of decedents dying on or after August 1, 2025, and adjusts this amount for each calendar year thereafter.

Additionally, the bill clarifies definitions related to the estate tax, including terms such as "decedent," "department," and "taxpayer." It specifies that the consumer price index used for adjustments will be based on the Seattle area and outlines the effective date of the act as August 1, 2025. The bill also states that certain existing sections of the law, specifically RCW 82.32.805 and 82.32.808, do not apply to this act, indicating a clear legislative intent to create a distinct framework for the estate tax adjustments.