There are two slightly different versions of the federal poverty measure: poverty thresholds and poverty guidelines.
The poverty thresholds are the original version of the federal poverty measure. They are updated each year by the Census Bureau. The thresholds are used mainly for statistical purposes — for instance, preparing estimates of the number of Americans in poverty each year. (In other words, all official poverty population figures are calculated using the poverty thresholds, not the guidelines.) Poverty thresholds since 1973 (and for selected earlier years) and weighted average poverty thresholds since 1959 are available on the Census Bureau’s Web site. For an example of how the Census Bureau applies the thresholds to a family’s income to determine its poverty status, see “How the Census Bureau Measures Poverty” on the Census Bureau’s web site.
The poverty guidelines are the other version of the federal poverty measure. They are issued each year in the Federal Register by the Department of Health and Human Services (HHS). The guidelines are a simplification of the poverty thresholds for use for administrative purposes — for instance, determining financial eligibility for certain federal programs.
The poverty guidelines are sometimes loosely referred to as the “federal poverty level” (FPL), but that phrase is ambiguous and should be avoided, especially in situations (e.g., legislative or administrative) where precision is important. The January 2018 poverty guidelines are calculated by taking the 2016 Census Bureau’s poverty thresholds and adjusting them for price changes between 2016 and 2017 using the Consumer Price Index (CPI-U). The poverty thresholds used by the Census Bureau for statistical purposes are complex and are not composed of standardized increments between family sizes. Since many program officials prefer to use guidelines with uniform increments across family sizes, the poverty guidelines include rounding and standardizing adjustments in the formula.
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