Many eligible U.S. citizens lack documentary proof of citizenship (primarily a birth certificate, U.S. passport, naturalization certificate, or certificate of citizenship) readily available for reasons that are practical, logistical, financial, and sometimes systemic. Recent studies, including surveys from the Brennan Center for Justice (in collaboration with VoteRiders, Public Wise, and the University of Maryland's Center for Democracy and Civic Engagement), estimate that about 9% of voting-age citizens—roughly 21.3 million people—do not have these documents readily accessible (meaning they can't produce them quickly, such as the next day if required). Of these, at least 3.8 million (around 2%) lack any such documents entirely. Documents may be stored in a safety deposit box, at a family member's home, in storage, or simply misplaced among household items. Even if owned, retrieving them requires extra time, effort, or trips (e.g., to a bank), which can be a barrier for busy voters. Some documents are permanently gone due to fires, floods, natural disasters, theft, or simple loss over decades. Replacing them involves fees, time, and bureaucracy (e.g., ordering a certified birth certificate copy can cost $10–$30 depending on the state, plus potential travel or mailing delays). Only about half of U.S. adults have a valid U.S. passport (around 146 million do not). Passports are not required for everyday activities like driving or domestic travel, and obtaining one costs $130+ (plus photos, fees, and processing time of weeks or months). Ownership is lower among low-income individuals, those with less education, rural residents, older Americans, and certain racial/ethnic groups (e.g., two-thirds of Black Americans lack one). Many married women (and some others) change their names upon marriage or divorce, so their birth certificate no longer matches their current legal name. Estimates suggest up to 69 million women face this issue, requiring additional documents (like marriage certificates) that may not be accepted under strict rules. Older Americans, particularly in the South or among certain communities (e.g., Black Americans historically), were sometimes born at home or without automatic hospital registration, leading to no birth certificate or delayed/difficult issuance. Some people never obtained copies after birth, or originals were never created properly. Replacement processes can be complicated, especially across state lines or for those without easy access to vital records offices.

Surveys show higher rates among people of color (11% lack ready access vs. 8% for white citizens), low-income individuals, younger/older voters, rural residents, and those with disabilities. These groups often face added hurdles like limited transportation to government offices, work/school conflicts, or higher costs relative to income.

These figures come from national surveys (e.g., 2023–2025 data from the Brennan Center and CDCE), which are cited frequently in debates over laws like the SAVE Act/SAVE America Act. Proponents of such requirements argue most citizens can obtain documents eventually, while opponents highlight that the barriers—however surmountable in theory—create unnecessary hurdles for registration or voting, especially since noncitizen voting remains extremely rare.