Longevity Steps STEP 19 = 11 years of, full-time service in the Murrieta Valley Unified School District with the exception of broken service caused by an allowable necessity in accordance with the definition of “Allowable Necessity” contained in Appendix F “Definition of Terms.” STEP 22 = 14 years of, full-time service in the Murrieta Valley Unified School District with the exception of broken service caused by an allowable necessity in accordance with the definition of “Allowable Necessity” contained in Appendix F “Definition of Terms.” STEP 25 = 17 years of, full-time service in the Murrieta Valley Unified School District with the exception of broken service caused by an allowable necessity in accordance with the definition of “Allowable Necessity” contained in Appendix F “Definition of Terms.” STEP 28 = 20 years of, full-time service in the Murrieta Valley Unified School District with the exception of broken service caused by an allowable necessity in accordance with the definition of “Allowable Necessity” contained in Appendix F “Definition of Terms.”