The American Community Survey (ACS) is the most widely used source of language data in the United States, largely because it is the only survey to provide language and English-speaking ability data for local communities. Language data users are a diverse group and include:

• Government agencies complying with laws protecting non-English language speakers or planning for future language resource needs.
• Businesses who utilize language data to make marketing plans or hiring decisions.
• Linguists, demographers, and other researchers.

In an effort to better serve these data users’ needs, the U.S. Census Bureau made some language data coding and presentation improvements in 2016. The goals of this overhaul included the following:

1. Produce more precise and granular language data without placing additional burden on ACS respondents or data collection operations.
2. Provide better data products for a variety of users across different levels of detail.
3. Conform ACS language data to the standards most widely used by translators.
4. Maintain comparability over time with past language data, whenever possible.

The changes seen in the 2016 ACS language data and beyond were a result of a process that took more than four years. The need for these updates was first noticed after the 2010 Census, when subject matter experts in the Education and Social Stratification Branch of the Social (ESSB), Economic and Housing Statistics Division identified the need for more uniform, standardized coding. Between 2013 and 2015, the new language code list was created. Between 2015 and 2017, implementation of the changes into ACS production took place. New data products for individual and household language data were designed in 2016, and were released to the public in 2017 and early 2018. This report describes the processes, decision points, and challenges involved in this redesign.