Resources on the Definition of LEP for Data Collection Purposes

The U.S. Census Bureau's American Community Survey and Puerto Rico Community Survey 2013 Subject Definitions defines "Limited English speaking households" as those in which "no one 14 and over either (1) speaks English at home or (2) speaks a language other than English at home and speaks English 'very well.'”
American Community Survey and Puerto Rico Community Survey 2013 Subject Definitions, page 47, available at:
http://www2.census.gov/programs-surveys/acs/tech_docs/subject_definitions/2013_ACSSubjectDefinitions.pdf

Many state and federal language access plans and guidance indicate that the Census should be used as a source of data collection for LEP data along with other sources. Therefore, they do not specifically say that LEP should be defined as “less than very well”.

The US Census does make a distinction between respondents who reported speaking English “very well” and those who reported speaking less than “very well” for reporting purposes. This distinction comes from the English Language Proficiency Survey (ELPS) conducted by the Census Bureau in 1982.  The ELPS concluded that those who spoke English less than “very well” had some difficulty with the tests administered in the ELPS. No study has been conducted since the 1982 ELPS.

• Attached is a powerpoint titled Using Data Sources to Identify LEP Populations which gives more insight into the definition of LEP.

• The Census Bureau uses four categories of English language ability for households that report speaking a language other than English at home: those that speak English “very well,” “well,” “not well,” and “not at all.” Those who speak English well, not well, or not at all are considered to have limited English proficiency.  See, e.g., 
  A Compass for Understanding and Using American Community Survey Data: What State and Local Governments Need to Know [PDF - 1.3 MB], available at:
  https://www.census.gov/library/publications/2009/acs/state-and-local.html

• According to the Migration Policy Institute, the term Limited English Proficient (LEP) refers to "any person age 5 and older who reported speaking English less than 'very well' as classified by the U.S. Census Bureau. The term English proficient refers to people who reported speaking English only or 'very well.'" 
  "The Limited English Proficient Population in the United States," July 8, 2015, available at:
  http://www.migrationpolicy.org/article/limited-english-proficient-population-united-states
  
  

Through conversation with an expert in the Social, Economic & Housing Statistic Section of the Education and Social Stratification Branch of the US Census Bureau, it appears that the Census does not define LEP as “less than very well” they make this distinction to group data, but they do not publically hold a position on what LEP should be defined as. With this in mind, the US Census did publish the above document, according to the US Census Bureau it was written by a contractor in the ACS section and does not reflect an official US Census Bureau definition.