When someone joins a congregational prayer in progress, what should he/she do and recite?

Assalamualaikum, When I join a jamat for a prayer, sometimes the first, or the first two rakkaths are already over. So, in this case, I finish the left out rakkaths on my own. So, if I join the prayer in the third rakkath, when I continue my prayer after the imam gives salam, should i recite alhamdhu surah and another surah like we do in the first two rakaths or is it enough if I just recite alhamdhu surah and go go to rukhu (like we do in the 3rd and 4th rakaths). Wasalam.

Dear Brother / Sister,

A person who cannot join the imam in the first rakat is called masbuq. (Late Comer) He joins the imam anyway. He reads only at-tahiyyat in the last sitting and keeps silent. He does not read salawat and other supplications. He can read tashahhud slowly till the imam completes the prayer. When the imam gives salutation to the right side, he does not; he waits for the imam to give salutation to the left side too. After the imam gives salutation to the left side, he stands up and completes the rakat(s) he has missed.
A person who joins the imam in the second rakat, stands up by saying Allahu Akbar after the salutations of the imam. He reads Subhanaka, al-Fatiha, and some verses from the Quran; then he sits after performing the ruku and sajdahs. He reads tahiyyat, salawat and other supplications and gives salutations.  
A person who joins the imam in the 3^rd rakat, performs two more rakats when he stands up by reading al-Fatiha, and some verses from the Quran.
If a person joins the imam in the fourth rakat, he stands up after the salutation of the imam and reads al-Fatiha and some verses from the Quran performing one rakat and sits. After reading tahiyyat, he stands up and performs two more rakats. What one should note here is to perform the first and second rakats in which al-Fatiha and some verses from the Quran are read first while praying alone because he has joined the imam in the fourth rakat in which only al-Fatiha is read. Two rakats with al-Fatiha and some verses from the Quran and one rakat with only al-fatiha remain. Therefore, after the salutation of the imam, he should read, al-Fatiha and some verses from the Quran in the first two of the remaining three rakats and only al-Fatiha in the last rakat.

To have more information, please read the article given below;

MASBÛQ (LATECOMER)

Masbuq is a person who has not caught up with the imam in the first rakat and jonied the congregational prayer after the first rakat. A person who catches up with the imam after the first rakat and joins the prayer before the imam gives the first salutation is regarded to have caught up with the prayer and he becomes subject to the decrees of masbuq. So, masbuq is a person who joins the congregation in the second rakat or tashahhud of a two-rakat player, in the second, third, fourth rakat or in the last tashahhud of a four-rakat prayer, in the second, third rakat or the last tashahhud of a three-rakat prayer.
The following decrees are applied about masbuq:
If Masbuq joins the congregation in a rakat when the Quran is recited aloud, he does not read “Subhanaka”; he says Allahuakbar and keeps silent. In the last tashahhud with the imam, he reads only "at-Tahiyyat"; when the imam gives the salutations, he stands up and read al-Fatiha and some verses from the Quran after reading audhu-basmala and completes the remaining rakats. If he joins the congregation when the imam is in the ruku or sajdah, he checks the situation. If he thinks that he can join some part of the ruku and sajdah when he reads “Subhanaka”, he reads it standing. Otherwise, he joins the congregation and does not read “Subhanaka”. If he joins the congregation in tahiyyat, he does not read “Subhanaka”; he recites takbir iftitah and sits (al-Fatawal-Hindiyya, Beirut 1400/1980, I, 90, 91).
After sitting as long as tashahhud in the last sitting, Masbuq can stand up without waiting for the salutation of the imam in the following situations:
a) If Masbuq is afraid that the period of his mash will end.
b) If Masbuq has an ‘excuse’ and if he is afraid that the time for prayer will end.
c) If he is afraid that the time of asr (afternoon) prayer will start in the prayer of Friday.
d) If he is afraid that the time for noon prayer will start in the eid prayer or the sun will rise in fajr (morning) prayer.
e) If he thinks that his wudu will be invalid, he should wait for neither the salutation of the imam nor sajdah sahw (prostration of forgetfulness).
f) If Masbuq thinks that people will walk in front of him while he is praying, he can stand up after tashahhud.
If he stands up without a reason or excuse after tashahhud, his prayer is valid. However, it is tahriman makrooh (strictly abominable). It is not permissible to stand up without sitting as long as tashahhud. If Masbuq completes his prayer before the salutation of the imam and follows the imam in salutation, it is possible and permissible. (al-Fatawal-Hindiyya, I, 91).
We can explain the situations that people who join the imam after the first rakat will face while completing the missing rakat in accordance with the characteristics of prayers as follows.
1) A person who joins the imam in the second rakat of the morning prayer recites takbir and keeps silent. He recites tahiyyat in the last sitting and stands up when the imam gives salutation; he starts performing the rakat that he has missed. After reading Subhanaka, he recites audhu basmala, al-Fatiha and some verses from the Quran. After the ruku and sajdahs, he sits and reads at-tahiyyat, salawat and rabbana atina; then he gives salutations.
2) If Masbuq joins the imam in the last rakat of the evening prayer, he reads Subhanaka and performs that rakat with the imam and sits in the tashahhud; then, he stands up and recites audhu basmala, al-Fatiha and some verses from the Quran. He sits after the ruku and sajdahs and reads only at-tahiyyat. Then he says Allahu Akbar and stands up. He reads basmala, al-Fatiha and some verses from the Quran and performs the ruku and sajdahs; then he performs the final sitting and gives salutations, finishing the prayer. Thus, he performs tashahhud three times. However, if Masbuq forgets and does not sit after the second rakat, sajdah sahw is not necessary for him because that rakat is regarded as his first rakat. 
3) If Masbuq joins the imam in the fourth rakat of a four-rakat prayer, he stands up after sitting for tashahhud with the imam. He reads audhu basmala, al-Fatiha and some verses from the Quran. He sits after the ruku and sajdahs and reads only at-tahiyyat. Then he stands up and reads basmala, al-Fatiha and some verses from the Quran and performs the ruku and sajdahs. He stands up without sitting and performs one more rakat reading only basmala and al-Fatiha and sits. He reads reads at-tahiyyat, salawat and rabbana atina; then he gives salutations. 
4) If Masbuq joins the imam in the third rakat of a four-rakat prayer, he reads only at-tahiyyat in the last sitting and stands up. He reads subhanaka, audhu basmala, al-Fatiha and some verses from the Quran and performs the ruku and sajdahs; then, he stands up, reads basmala, al-Fatiha and some verses from the Quran and performs the ruku and sajdahs; He sits and reads at-tahiyyat, salawat and rabbana atina; then he gives salutations, finishing his prayer. 
5) If Masbuq joins the imam in the second rakat of a four-rakat prayer, it means he has performed three rakats with the imam; after tasahhud, he stands up and reads subhanaka, audhu basmala, al-Fatiha and some verses from the Quran and performs the ruku and sajdahs. Then he performs the last tashahhud and completes his prayer with salutation. 
6) A person who joins the imam when he is in the ruku, he is regarded to have caught up with that rakat. However, if a person who joins the imam when he is in sajdah, he is regarded to have missed that rakat. Therefore, he needs to complete that rakat in accordance with the descriptions above. 
7) It is not permissible for Masbuq to join another imam for the rakat(s) he has missed; it is not permissible for somebody else to join Masbuq in the rakat(s) he has missed. Masbuq is not regarded as praying alone regarding the issue. However, if Masbuq forgets how many rakats he has missed, he can take into consideration the state of another Masbuq; his prayer is not regarded invalid if he does so.  
8) If Masbuq recites takbir iftitah with the intention of performing the prayer again, his previous prayer with the previous takbir becomes invalid. A person who prays alone, is not like that; unless he intends to perform another prayer, a new takbir for the same prayer does not invalidate his prayer because both prayers are the same in comparison to the one praying alone. As for masbuq, he is alone in his aspect; he does not have the same situation in terms of joining the imam. 
9) According to Abu Hanifa, Masbuq recites the tashrik takbirs together with the imam and then stands up and completes the missing rakat(s) in the prayer of eid al-Adha. According to Abu Hanifa, a person praying alone does not have to perform those takbirs. Therefore, Masbuq is not regarded as a person praying alone but as a person who has joined the imam regarding the issue. 
10) If Masbuq finishes tahiyyat before the imam gives salutations, according to a view, he reads kalima shahada again; according to another view, he keeps silent. What is the sound view is that Masbuq should read tahiyyat slowly. A person who finishes reading tahiyyat before the imam should keep silent.
11) If imam stands up for the fifth rakat by mistake and if Masbuq stands up with him, it is checked whether the imam has sat after the fourth rakat or not; if the imam has sat, the prayer of Masbuq becomes invalid when the imam stands up; if he has not sat, the prayer of Masbuq does not become invalid until the imam goes to sajdah for the fifth rakat. 
12) It is possible for Masbuq to become also Lahiq (a person who joins the imam at the beginning of the prayer but then has to leave the prayer). If a person who joins the imam after the first rakat misses a pillar of the prayer or a rakat or rakats due to sleep or the breaking of wudu, he becomes both Masbuq and Lahiq. Then, he completes the rakats that he has missed without reading and joins the imam if possible for the rest of the prayer; then, he performs the rakat(s) that he has missed before joining the imam by reading. It is permissible for him to perform the rakat(s) that he has missed before joining the imam first and perform the ones that he has missed after joining the imam later. However, then, he is regarded to have committed a sin by not observing the legitimate order.

In conclusion, the aim of the decrees about Masbuq and Lahiq is to encourage Muslims to perform prayers in congregation and to provide convenience for those who have missed the beginning of the prayer or those who have not been able to perform the whole prayer with the imam. Prayer in congregation is very important in Islam and it has been stated that praying fard in congregation is twenty-seven times more virtuous than praying it alone. (For masbuq see Molla Khusraw, Durarul-Hukkam, İstanbul 1307, I, 92 et al.; al-Fatawal-Hindiyya, Beirut 1400/1980, I, 90 et al.; Ibnul-Humam, Fathul-Qadir, Egypt 1389/1970, I, 377 et al.; Ö. Nasuhi Bilmen, Büyük İslâm İlmihali, İstanbul 1985, s. 186 vd.).
Şamil İslam Ansiklopedisi

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