Updating the inflation adjustment for the estate tax exclusion amount.

SB 5405 updates Washington's estate tax exclusion amount to adjust annually for inflation starting in 2026. It replaces the current fixed $2,193,000 threshold with a formula that increases the exemption each year based on the Seattle metropolitan area consumer price index (CPI). The adjustment multiplies the base amount by (1 + inflation rate) and rounds to the nearest $1,000, ensuring the exclusion keeps pace with rising costs. This directly affects Washington residents and others with taxable estates exceeding the inflation-adjusted threshold, particularly for decedents dying in 2026 or later.