Depending on the institution where the senior would like to audit classes, doing so may be as simple as contacting the professor of a particular course and determining if their is classroom space for an auditor. Some institutions, such as Hunter College, impose a small prerequisite fee.
Each school has its own system for allowing senior citizens to audit classes. Most of the relevant information about the process of senior citizens auditing classes is on a school's website. Schools may offer senior citizens the opportunity to audit specific classes, or there may be an entire program in place to accommodate senior citizens, such as the Senior Scholars program at the University of California, Los Angeles.
The Senior Scholars program allows participants to take any class, providing there is space in the classroom and the professor approves. Senior Scholars pay reduced tuition. Columbia University has a similar program called the Lifelong Learners Auditing Program. Prospective applicants must complete an application, pay a non-refundable application fee and, as of May 2015, reduced tuition of approximately $75 per credit.
Senior citizens interested in auditing classes at Hunter College must submit a non-degree application and must be New York State residents. The University of Houston allows senior citizens to audit classes for free, but there must be space in the classroom.