Each year approximately fifteen high school students, at least 14 years of age, are selected to be members from a large pool of applicants. Over the course of their four-year career at Post 53, members progress through five roles: Candidate, Radio Roomie, Rider, State-Certified EMT, and then Driver, usually by their Senior year.

Post 53 members take academics very seriously. Over 88% of Post 53’s young adults are on the honor or high honor roll at Darien High School compared to 50% for the average DHS student body.

Training and the personal ability to be a team player are the cornerstones of membership in Post 53. From their first day, members take on increasing levels of responsibility and are expected to earn the privilege of serving on the ambulance. Here's a description of "the Career of a Postie" in greater detail:

First Aid Class: A career in Post 53 begins when a student, in the summer following 8th grade or during freshman year, enrolls in a First Aid/CPR class, taught by young adult members of Post 53. This training includes 25 hours of class time over a three month period. Those with demonstrated ability and maturity are chosen from each class to become candidates for membership.

Candidate: Over the next three months, these young adult candidates attend all business meetings, training meetings and work parties, and spend a minimum of one hour daily at Post 53 headquarters to familiarize themselves with operational procedures and the overall program. Each candidate has a sponsor. “Successful candidates display First Aid ability, character, personal commitment, helpfulness to the organization, dependability and acknowledgement of the privileges of membership" (Post 53 ByLaws). After this three months of candidacy and duties in the Radio Room, candidates are voted on for full membership by all young adult members of Post 53.

Radio Roomie: Radio Roomies are responsible for communications at Post 53's Headquarters, recording times of ambulance calls, answering telephones and responding to pages by the Darien Police Dispatcher. It is the Radio Roomie's responsibility to control the environment in the radio room while monitoring the communications of all area emergency service.

Rider: To become a member of the ambulance crew, a member must first learn the location and use of all equipment on the ambulance and pass both written and practical tests. Riders assist the EMS crew on ambulance calls by anticipating what equipment is required and assist with care as needed. In their Sophomore year, Riders who have demonstrated the requisite skills, interest and dedication are recommended by Post 53 officers and the Director of Training to begin the EMT course given at Post 53 headquarters.

Emergency Medical Technician (EMT-Basic): The EMT is responsible for all patient care at the basic level and radio communications with the receiving hospital. The Emergency Medical Technician course is approximately 140 hours over a period of six months. In addition to classroom work, training includes hospital Emergency Room rotations. Participants must pass the State practical and written exam an receive their official certification at 16 years of age.

Ambulance Driver: To be eligible for the role of ambulance driver, a young adult EMT must have at least six months driving experience and a clean driving record. They must pass rigid practical and written tests. At the beginning of each shift, drivers are responsible for checking all systems on the ambulance, i.e., lights, sirens, radios, gas, tires, etc. The Driver's main responsibility is to get the ambulance to the scene and to the hospital safely with proper consideration for the condition of the patient and road safety.

Crew Chief: (must be an EMT) The most experienced and skilled (BLS) members, usually in their Senior year, are selected by the Officers and the Advisor to become Crew Chiefs based upon patient care, leadership and overall maturity.