This study examines production errors in ASL lexical phonology by beginning L2 adult learners, more particularly the handshape, location, movement, palm orientation, and nonmanual phonological segments. Studies in L2 adult learning of ASL are scant. For possible analytical models, first and second language acquisition models such as L1 transfer, Universal Grammar, and L1 child development are examined. The models do not capture the essence of phonology production errors in L2 ASL. A Cognitive Phonology Model is proposed to account for the errors. The errors are shaped by perception of sign formulation and poor motor dexterity. Production errors that are influenced by poor motor dexterity by adult L2 learners consist of substitutions, displacements, switches, additions, deletions, and incompletions of features within segments. Production errors that are shaped by perception of sign formulation consist of mirrorization, parallelization, addition, and deletion of features within segments.For adult learners whose first languages (L1) are spoken, learning American Sign Language (ASL) lexical phonology as a second language (L2) for the first time presents challenges. Producing a lexical system of a language requires incorporating its articulatory segments. Beginning L2 learners of ASL need to learn the visual-manual articulatory segments in ASL. In the course of learning ASL phonological rules for lexical items the L2 learners frequently make production errors. How should beginning L2 production errors in ASL lexical phonology be analyzed and explained? Studies in the production of lexical phonological system of ASL by L2 learners are scant. To assess possible models of analysis and explanation of L2 lexical phonology production errors, I review three models of first and second language acquisition.