The target/initial population refers to the cohort from which to select the denominator population. Some measures (e.g., ratio measures) require multiple target/initial populations, one for the numerator and one for the denominator.

Details often include information based on specific age groups, diagnoses, diagnostic and procedure codes, and enrollment periods.

If the measure is part of a measure set, the broadest group of population for inclusion in the set of measures is the target/initial population. The measure developer must specify codes or other data necessary to identify this cohort, as well as any sequencing of steps needed to identify cases for inclusion.