Mahoney's training required she spend at least one year in the hospital's various wards to gain universal nursing knowledge. The work within the program was intensive and consisted of long days with a 5:30 A.M. to 9:30 P.M. shift, requiring Mahoney to attend lectures and lessons to educate herself through instruction of doctors in the ward. These 12 hour lectures classes consisted of nursing in families, physiological subjects, food for the sick, surgical nursing, child-bed nursing, disinfectants, and general nursing. Outside of the lectures, students were taught many important bedside procedures such as taking vital signs and bandaging. In addition, Mahoney worked for several months as a private-duty nurse. The nursing program allowed for the students to earn a weekly wage, ranging from 1 to 4 dollars, after their first two weeks of work. Many nurses did not see the weekly wages as significant, as many of them were struggling financially and thus were giving back 25% of their wages for financial assistance to the hospital. Three quarters of the program consisted of the nurses working within a surgical, maternity or medical ward with six patients they were responsible caring for. The last two months of the extensive 16-month long program required the nurses to use their newfound knowledge and skills in environments they were not accustomed to; such as hospitals or private family homes.After completing these requirements, Mahoney graduated in 1879 as a registered nurse alongside 3 other colleagues — the first Black woman to do so in the United States.