We describe the development and initial validation of the "ASL Fingerspelling and Number Comprehension Test" (ASL FaN-CT), a test of recognition proficiency for fingerspelled words in American Sign Language (ASL). Despite the relative frequency of fingerspelling in ASL discourse, learners commonly struggle to produce and perceive fingerspelling more than they do other facets of ASL. However, assessments of fingerspelling knowledge are highly underrepresented in the testing literature for signed languages. After first describing the construct, we describe test development, piloting, revisions, and evaluate the strength of the test's validity argument vis-à-vis its intended interpretation and use as a screening instrument for current and future employees. The results of a pilot on 79 ASL learners provide strong evidence that the revised test is performing as intended and can be used to make accurate decisions about ASL learners' proficiency in fingerspelling recognition. We conclude by describing the item properties observed in our current test, and our plans for continued validation and analysis with respect to a battery of tests of ASL proficiency currently in development.