From the news release:
The supplemental poverty measure serves as an additional indicator of economic well-being and provides a deeper understanding of economic conditions and policy effects.
Unlike the official poverty rate, the supplemental poverty measure takes into account the impact of different benefits and necessary expenses on the resources available to families, as well as geographic differences in housing costs. For example, the measure adds refundable tax credits to cash income, which reduces the supplemental poverty rate for all people by nearly three percentage points (18.4 percent to 15.5 percent). For children, the supplemental poverty rate of 16.4 percent would rise to 22.8 percent if refundable tax credits were excluded.Last year's report found that California had the nation's worst poverty rate.
According to this year's supplemental measure, California again has the nation's highest poverty rate.