Prayer: Forgetting a Sajdah and Sajdata al-Sahw in the Eid Prayer
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 1511
If a person forgets a sajdah in the Eid prayer, it is necessary that he perform it after the prayer. Similarly, if something happens [in the Eid prayer] that would necessitate sajdatā al‑sahw to be performed were it to happen in a daily prayer, then it is necessary to perform sajdatā al‑sahw for it.