Modifies provisions relating to the Missouri working family tax credit act and makes the tax credit refundable

HB 1554 modifies Missouri's Working Family Tax Credit to make it refundable for tax years beginning on or after January 1, 2026, meaning eligible taxpayers can receive a cash refund if the credit exceeds their state tax bill (unlike prior years, where excess credits were not refunded). The bill sets the credit at 10% of the federal Earned Income Tax Credit (EITC) for 2023, with a potential increase to 20% if Missouri's net general revenue growth meets a specific threshold (a $150 million increase over the previous three years' peak). It requires the state Department of Revenue to proactively notify eligible taxpayers who may not have claimed the credit and to publish annual reports on credit usage, including income-level distribution. This credit directly affects Missouri residents filing as single, head of household, widowed, or married filing jointly who qualify for the federal EITC.