The Workplace Outcome Suite© (WOS) is a self-report instrument designed to evaluate the effectiveness of employee assistance program (EAP) counseling services from the perspective of the employee user of the service. More than 30 EAPs collected longitudinal data on all versions of the WOS from 2010 to 2018 and voluntarily submitted their raw data to Chestnut Global Partners for analysis. The 24,363 employees in this aggregated sample represent 26different countries, but most of the cases were from the United States (79%) and China (15%). The typical EAP case in this data set was a female, age 38, and was a self-referral into an external vendor of EAP services seeking help for a mental health concern. Outcomes were collected at the start of counseling and again approximately three months later. Evidence of the psychometric validity and test-retest reliability for all five WOS measures was found in correlational tests. Other tests of the change in outcomes from before to after use of EAP counseling found large effects on work presenteeism and life satisfaction (ηp2= .24 and .19), a medium-size effect on work absenteeism (ηp2= .13), and small effects on both workplace distress and work engagement (ηp2= .05 and .04). Although most EAP cases had no absence from work either before counseling or at follow-up (58% and 78%, respectively), the average amount per case per month of missed work due to the personal concern was reduced from 7.4 hours before to 3.9 hours after use of the EAP. Weak findings on moderator tests determined EAP counseling was effective to a similar degree on WOS outcomes across contextual factors of client age, sex, country, referral type, clinical concerns, industry of the employer, and delivery models for providing employee assistance counseling (i.e., external vendors, internal staff programs and hybrid models). As an alternative to the fill-in-the-blank response format requiring a specific number of hours, a modified version of the work absenteeism single item is offered that has a 5-point scale with normative levels of absence hours obtained from the Pre EAP use global data that define each of the 1-5 rating options. More details and related findings are presented in the Workplace Outcomes Suite 2018 Annual Report from Chestnut Global Partners.