Can I perform volunteer work while visiting the United States on a B-2 tourist visa?

Generally, you are strictly prohibited from engaging in any form of 'employment' while in the U.S. on a B-2 tourist visa. Employment is defined as services rendered for which one receives compensation, whether in cash or in-kind benefits. However, the Department of State and USCIS distinguish between 'employment' and 'volunteerism.'

True volunteer activities—such as helping at a food bank, participating in a church service project, or assisting a non-profit organization in a capacity that does not displace a U.S. worker—are often permissible provided that you do not receive any remuneration or benefit. The key is that the activity must be for a charitable purpose and there must be no expectation of payment. If you are assisting a business or an organization in a role that would typically be a paid position, immigration officers may view this as unauthorized employment, which is a violation of your B-2 status. If you are caught working or engaging in activities that look like unauthorized employment, your visa may be revoked, and you could be barred from re-entering the United States. If you intend to participate in significant volunteer work, it is highly recommended to consult with an immigration attorney to ensure your activities do not cross the line into unauthorized work.