Certified medical assistant duties vary from office to office; generally, these non-licensed professionals perform a variety of administrative and clinical tasks under the direction of an office manager or physician. Administrative duties can include answering telephones, greeting patients, scheduling appointments, filing insurance paperwork and updating medical records.

In addition, certified medical assistants may be required to perform clinical work, such as taking medical histories, recording vital signs or preparing patients for exams. Other clinical tasks might include collecting and preparing lab specimens, performing basic lab tests and sterilizing medical equipment.

Some medical assistants work one-on-one with patients while drawing blood, administering medications, advising on treatment plans, prescribing a specialized diet, removing sutures or changing dressings. Other duties might include cleaning both waiting and examination rooms or ordering supplies and equipment for the medical office.

Medical assistants must have certification in the field. The American Association of Medical Assistants (AAMA) requires candidates for certification to have completed an accredited medical assisting program. Most such programs run two years and result in an associate's degree; community and junior colleges as well as vocational schools offer them. Some programs last one year and result in a certificate. The AAMA also requires that candidates complete an unpaid work experience program called a practicum, and then they must pass an exam. Recertification is required every five years.

Certification for medical assisting can also be obtained through American Medical Technologists (AMT), which has basically the same requirements of AAMA certification but does not require passage of an exam if the candidate has been working in the field of medical assisting for three of the past five years or if they have previously passed a certification exam.

In addition to medical assisting certification, some jobs require applicants to be certified in basic life support, which trains individuals to respond to life-threatening situations like heart attacks, choking or drowning.