This study explores patterns of ethnic boundary crossing as evidenced by changes in Hispanic origin responses across decennial census and survey data. We identify socioeconomic, cultural, and demographic factors associated with Hispanic response change. In addition, we assess whether changes in the wording of the Hispanic origin question between the 2000 and 2010 censuses influenced changes in Hispanic reporting. We use a unique large dataset that links a person’s unedited responses to the Hispanic origin question across Census 2000, the 2010 Census and the 2006-2010 American Community Survey five-year file. We find that most of the individuals in the sample identified consistently as Hispanic regardless of changes in the wording of the Hispanic origin question. Individuals who changed in or out of a Hispanic identification, as well as those who consistently identified as non-Hispanic (of Hispanic ancestry) differed in socioeconomic and cultural characteristics from individuals who consistently reported as Hispanic. Changes in Hispanic origin response is higher among U.S.-born individuals reporting mixed Hispanic and non-Hispanic ancestries, those who speak only English at home, and those who live in tracts that are predominantly non-Hispanic. Racial identification and detailed Hispanic background also influence changes in Hispanic origin responses. Finally, changes in mode and relationship to the reference person in the household are associated with changes in Hispanic origin responses, confirming that data collection elements influence response change.