This article investigates discursive practices associated with the co-management of patients between healthcare providers. Specifically, we focus on two genres (38 referral letters and 37 consultant reports) written by optometrists and ophthalmologists — two groups who are experiencing interprofessional tension over their scopes of practice. In our analysis we foreground four kinds of modality associated with verbs — epistemic, deontic, phatic and subjective. We found that these healthcare providers shared in the epistemic resources used to hedge their sense of clinical certainty, and that ophthalmologists used deontic resources to control future action. However, we also noted that both professions used deontic, phatic and subjective resources to create dialogical space for each other to participate in some future relationship. In fact, one of the main points of this correspondence might be to establish personal relationships between practitioners. Unfortunately, however, this subtle use of modality to negotiate professional boundaries is fading as many ophthalmologists, due to workload issues, are not responding to referral letters or are converting their correspondence to form letters.