The Supplemental Poverty Measure (SPM) is a measure of economic deprivation-having insufficient financial resources to achieve a specified standard of living. The SPM addresses some of the limitations of the official poverty measure, without supplanting it outright. Both the SPM and the official measure determine the poverty status of people and families by comparing their financial resources against poverty thresholds that are valued in dollars. For both measures, poverty thresholds vary by family size and composition, and families whose resources are lower than the thresholds are considered to be poor. The measures differ in their definitions of • need, as it is used in the thresholds (the dollar amounts used to determine poverty status), • financial resources that are considered relevant for comparing against the measure of need as specified in the thresholds, and • family, for the purpose of assigning thresholds and counting resources. Need The official poverty measure thresholds are based on the costs of austere food budgets developed using data from the 1950s and 1960s, with the threshold dollar amounts updated annually for inflation. The official poverty thresholds vary by family size and composition. In contrast, the SPM thresholds for any given year are based on a below-median level of consumer expenditures for food, clothing, shelter, and utilities developed using data for five recent years. The SPM thresholds vary to reflect that • housing costs differ between homeowners with mortgages, homeowners without mortgages, and renters; • housing costs differ geographically; and • costs differ by family size and composition. Financial Resources Financial resources to meet needs, whether in the SPM or the official measure, are based on the sum of income of all family members. While the official measure uses money income before taxes, the SPM makes additional adjustments and considers a wider range of resources. The SPM includes the value of certain in-kind benefits (such as food and housing subsidies), uses income after estimated federal and state taxes, and subtracts some expenses from income. These expenses include medical out-of-pocket costs, such as health insurance premiums, physician co-pays, and over-the-counter medications; child support paid outside of the household; and work expenses, such as child care and the cost of commuting, tools, uniforms, or licensing fees related to a person's employment. Work expenses, including child care, are capped at the amount of earnings from work of the lowest-earning family member. These expenses are subtracted from family income because they cannot be used to obtain the needs defined in the SPM thresholds. Unlike the official poverty measure, the range of financial resources included in the SPM is defined to be consistent with the types of needs used to compute the SPM poverty thresholds. Family Like the official measure, the SPM family unit definition includes people related by birth, marriage, or adoption living in the same housing unit. However, the SPM additionally includes cohabiting couples and their children, and foster children below age 22. How Does Poverty Look through the Lens of the SPM? The demographic profile of the poverty population is different under the SPM than under the official measure. Children have a comparatively lower poverty rate (percentage in poverty) under the SPM, and the aged (65 and older) have a comparatively higher poverty rate. Among workingage persons (18 to 64), the SPM poverty rate was lower than the official rate in 2020, although in previous years the reverse was true. These differences can be explained by the SPM's resource definition. The SPM includes tax credits and in-kind benefits that help families with children (in effect, boosting the measure of family income). Stimulus payments sent to households in 2020 help to explain the comparatively lower poverty rate among working-age persons in the SPM that year compared to the official measure. Typically, however, because the SPM subtracts workrelated expenses, the income for working-age adults appeared lower under the SPM than the official measure (before 2020), and as a result their SPM poverty rates had been comparatively higher. The SPM also subtracts medical out-of-pocket expenses, which disproportionately affects the aged (lowering their measure of income). Uses and Limits The SPM can give policymakers the tools to understand how taxes and government programs, including the noncash programs, affect the poor. It also illustrates how medical expenses and work-related expenses such as child care can affect a family's economic well-being. However, the SPM poverty estimates are derived from household survey data, and hence are affected by issues such as underreporting of income from government benefit programs, limitations on how tax liabilities and tax benefits can be estimated based on survey data, and differences in how noncash benefits and lump-sum tax refunds are valued by program recipients versus how they are valued for the purposes of poverty measurement. Additionally, the SPM does not directly value health insurance provided publicly or privately. Further, poverty has historically been measured in the United States as an absolute measure, based on how many people fall below a set standard of living. Questions have been raised about whether the SPM continues to measure poverty in that way, or represents a relative measure of poverty, based on how portions of the population rank in terms of well-being relative to each other. [ABSTRACT FROM AUTHOR]