Subspecialty and Combined Training Careers

Although this section of IMpact explores the subspecialty and combined training careers on internal medicine, it's worth emphasizing what makes internal medicine unique. Internal medicine physicians see things differently. Holistically. And in a unique way that allows them to analyze, lead, and humanize health care in a variety of different settings and roles. See all the career opportunities internal medicine can provide.

Infectious Disease

The Discipline

Infectious disease medicine is the subspecialty of internal medicine that focuses on diagnosing and managing infections. Although most common infections are treated by general internal medicine physicians and other specialty physicians, internal medicine physicians practicing infectious disease medicine are frequently called upon to help diagnose unknown infections and assist in managing difficult, unusual, or complicated infections.

Infectious disease medicine requires an extensive understanding of the way in which bacterial, viral, fungal, and parasitic infections occur in humans and how they present clinically, as well as knowledge about antimicrobial agents, antibiotic resistance, vaccines, and other immunobiological agents. Because of their training, infectious disease internal medicine physicians are also uniquely equipped to deal with the environmental, occupational, and host factors that predispose to infection, as well as the basic principles of epidemiology and transmission of infection.

There are many different models of infectious disease practice. Some infectious disease physicians work in a dedicated infectious disease clinic or may split their infectious disease practice with general internal medicine practice. Many infectious disease physicians serve as consultants to other physicians, seeing patients in consultation in their practice or in the hospital, and they may also follow patients with certain infections longitudinally for ongoing care. Some internal medicine physicians practicing infectious disease medicine work in dedicated settings caring for specific patient populations requiring unique knowledge and skills (such as HIV or wound care clinics). Many doctors in infectious disease practice serve as hospital or community-based epidemiologists or infection control experts. In academic settings, infectious disease physicians may provide consultative and ongoing care in ambulatory and inpatient settings, perform basic science and clinical research in infectious diseases, and teach medical students and residents.


Training in infectious disease medicine is two years following completion of a basic three-year internal medicine residency. Board certification is offered following completion of an infectious diseases fellowship through the American Board of Internal Medicine.

Training Positions

In this 2023-2024 academic year, there are 168 Accreditation Council for Graduate Medical Education (ACGME)-accredited training programs in infectious disease with 830 trainees.

Major Professional Societies

  • Infectious Diseases Society of America

See all the career pathways open to internal medicine physicians.

Back to the October 2023 issue of ACP IMpact