The present study investigated the dominant verb-phrase structure and the semantic functions of the modal "must" in research papers. It also determined whether the modal "must" conforms to or deviates from the standard modal usage in American English. A total of 122 graduate research papers were analyzed. The findings revealed that the dominant-verb phrase structure of the modal "must" was must + base form of the verb and Filipino graduate student researchers most favor the obligation/compulsion/advisability function of the modal must. Moreover, the results of the present study substantiated Morales' (2015) linguistic assumption that the obligation function of the modal must has a continuous usage in Philippine English and further confirmed the findings of Gustillo (2011) that the modal "must" in Philippine English maintains its conformity to the standard modal usage in American English.