Gemara:

Berachot 

Halacha:

Beit HaKenesset,  Tefillah 

Machshava:

Tefillah 

Collections: R' Grunstein Minyan

References: Berachot: 7B ,  Berachot: 8A ,  Berachot: 6A  

Description

Despite the Code's formulation of going to Minyan as ישתדל/try, based on the Gemara's account of R' Yitzchak not going "out of his way" to get to a minyan (and not even have 9 others brought to his house), R' Moshe Feinstein saw it as an absloute obligation and Mitzva.