It is not uncommon for federal employees to be detailed to a higher grade or different position and then want to use that detail or temporary assignment as creditable experience when applying for a new position or a promotion, but you must document it properly in order to include in your application.
The Office of Personnel Management (OPM) assumes that employees gain experience by performing duties and responsibilities appropriate to their official position description, occupational series, and grade. If you want to be credited for experience outside your official position description, whether at a higher grade or in a different job series, your temporary work must be appropriately documented.
Such documentation could include a SF-52 or SF-50 that documents an official detail or assignment. It could also include a signed letter from the employee’s supervisor.
That letter must state the nature and length of the temporary assignment / detail, whether the duties performed were full- or part-time, and the percentage of time other duties were performed. The documentation should be included in an employee’s Official Personnel Folder (OPF).
Employees should submit the official documentation, along with their resume, when applying for positions where the temporary experience may be needed to support their application.