An Act relative to income tax rates

This bill modifies Massachusetts income tax rates and personal exemptions for tax years beginning in 2025 and later. It sets a flat 6.0% tax rate on Part B taxable income starting in 2025 and establishes three annual personal exemption amounts: $6,600 for single filers, $10,200 for heads of household, and $13,200 for married couples filing jointly. Starting in 2026, these exemptions will automatically increase each year based on inflation-adjusted tax revenue growth, provided specific thresholds are met. The adjustments require annual reports from the tax commissioner to state legislative committees by October and December. The changes directly affect individual taxpayers filing state income tax returns under these categories.