High productivity by behavioral health consultants (BHC) is a defining aspect of the primary care behavioral health (PCBH) model to maximize access to care and is often measured by patient volume. Studies of productivity in health care settings suggest a single productivity target may not be optimal. We used a Delphi method to obtain expert consensus on an operational definition of high productivity by BHCs in the PCBH model. Clinicians, managers, and researchers in PCBH were recruited to participate in a multi-round survey using a modified Delphi technique and develop consensus on PCBH productivity metrics. Ten participants completed all three survey rounds and rated 28 metrics. After three rounds, two direct metrics (average number of billable BHC visits each day; number of patients seen per day) received at least 80% consensus as “Essential”, two received at least 50%, and five received less than 50%. One influencer (level of integration at the practice) received at least 80% consensus as “Very Much” influential, 19 received at least 50%, and eight items received less than 50%. Several themes arose from participant comments. PCBH productivity can be interpreted as being high volume. Numerous practice factors influence how productive a BHC may be. Future studies should determine the feasibility of our metrics in clinical practice, establish productivity expectations based on patient needs and clinic resources, and identify patient-, clinician-, or practice-level moderators of productivity.