If someone forgot to pray the Amidah and its time has passed, they must recite a make-up prayer (Tefilat Tashlumin) after the next Amidah they pray: if one forgot Maariv, they should recite a second Amidah after Shacharit; if they forgot Shacharit, they should pray a second Amidah after Minchah. The make-up prayer must be recited right after the regular prayer. If a significant delay occurs between them, the opportunity for Tashlumin is lost. Between the two Amidot, there should be a brief pause—after tachanun of Shacharit one should say Ashrei and after Minchah or Maariv one should say a Psalm before reciting the make-up prayer.
In contrast to prayer, which can be made up, the halacha regarding Kriyat Shema (the recitation of the Shema) follows what our Sages said: “What is a crooked thing that cannot be corrected? One who neglected the Shema of the evening or the morning.” This means even if a person is careful from now on to always recite the morning and evening Shema, it does not make up for the unique light and holiness that was lost by missing it at its proper time.
Adapted and translated from Sichat HaShevua
