You are here

Mobility / Stability Statistics - FAQs

Q: Under what circumstances is a student counted as "mobile"?

A: In general, a student is considered mobile any time he or she enters or exits a school or district in a manner that is not part of the normal educational progression. Examples of normal progression include advancing grades between academic years, matriculating between elementary school and middle school or between middle school and high school, and exiting as a graduate or completer at the end of the twelfth grade. "Unanticipated" or "non-normal" movements – such as a mid-year grade advancement, entry into a school or district after October 1, or exit from a school or district before the end of the school year – are considered instances of student mobility.

Q: What is the difference between the Student Mobility Rate and the Mobility Incidence Rate?

A: The Student Mobility Rate is an unduplicated count – meaning that once a student has been counted as mobile once for a given school or district she or he will not be counted again in the same year. In contrast, the Mobility Incidence Rate is a duplicated count. A student who moves in and out of a school multiple times will be counted as mobile multiple times under the Mobility Incidence Rate calculation.

The Student Mobility Rate Calculation:

Unduplicated count of grade K-12 students who moved into or out of the school or district in Year X


Total number of students that were part of the same membership base at any time during Year X

The Mobility Incidence Rate Calculation:

Duplicated count of grade K-12 students who moved into or out of the school or district in Year X


Total number of students that were part of the same membership base at any time during Year X

Example: During the 2017-18 school year, student John Smith transfers from district A to district B. Later that same year, John transfers back to district A for two months, then moves out of the state before the end of the school year.

  • This would be counted as one instance of Student Mobility for District A (one student moved three times)
  • This would be counted as one instance of Student Mobility for District B (one student moved in and out of the district)
  • This would be counted as three instances of Mobility Incidence for District A (two exits and one late entry)
  • This would be counted as two instances of Mobility Incidence for District B (one late entry and one early exit)

Q: What is the difference between the school mobility rates and the district mobility rates?

A: If a student transfers from one school to another within the same district, the student is not counted as mobile at the district level (because the student did not enter or exit the district). However, both schools would count the student as mobile as part of the school mobility rates.

Q: How are the State Mobility Rates calculated?

A: The state pupil count (the denominator for both mobility rates) is the sum of the pupil counts for all districts. Similarly, the total mobile student count and the total instances of mobility (the numerators for the Student Mobility Rate and the Mobility Incidence Rate, respectively) are the sum of the district totals in these two categories.

Q: Did the mobility rate calculation change in the 2017-2018 school year?

A: The mobility calculation timeframe was modified in the 2017-2018 school year so that only entries and exits that occur from the October Count date to the end of the school year are included in the calculation. Students must have a gap in attendance of more than 10 days for a move to be considered mobile.

For additional information, email Reagan Ward, ward_r@cde.state.co.us