To meet criteria for dual coverage, the member should have dual coverage at the end of the continuous enrollment period (dual coverage is assessed on a measure-by-measure basis). For example, if a measure's continuous enrollment period ends on December 31 of the MY and has dual Medicaid and commercial enrollment on that date, then the member may be excluded from the Medicaid HEDIS reports for the measure and only be reported in the commercial product line (General Guideline 23 in HEDIS 2018 Volume 2). In cases where the member is dually enrolled in two Medicaid plans, the secondary Medicaid payer would have the choice to exclude the member if the primary Medicaid coverage was offered through a different organization.
HEDIS 2018