International TAPS Day is observed worldwide every March 3 to promote awareness of twin anemia polycythemia sequence (TAPS), a condition affecting identical twins who share a placenta. Established in 2021 by the TAPS Support Foundation, this day commemorates two significant papers published in March 2006 that contributed to the understanding of TAPS. The condition arises from small blood vessel connections between the twins, leading to anemia in one twin and polycythemia in the other. It is distinct from twin-to-twin transfusion syndrome (TTTS), which involves larger blood vessel connections and affects blood volume. On this day, efforts are made to educate both the medical community and the public about TAPS, its diagnosis, and treatment options, emphasizing the importance of recognizing it as a separate condition from TTTS. International TAPS Day should not be confused with World TAPS Awareness Day, observed on December 8.