In total it takes a full 12 years of schooling and education to become a fully licensed anesthesiologist.
The 12 years to become an anesthesiologists accounts for 4 years of medical school, 4 years of undergraduate study and 4 years of residency.
Although sometimes it's possible to enroll in a combined six-year undergraduate and medical school program, which can reduce the time needed to begin a career as an anesthesiologist.