DA Form 2173, Statement of Medical Examination and Duty Status is used in cases of either a formal or an informal Line of Duty (LOD) determination process. The latest fillable version of the form can be downloaded below.
An LOD is initiated when a service member sustains an injury or illness that results in an inability to perform military duties, the possibility of permanent disability or death.
The LOD investigations can be formal or informal. Informal investigations call for a copy of DA Form 2173 completed by the medical treatment facility and the unit commander and approved by the appointing authority.
A formal LOD determination is a detailed investigation that normally begins with the medical treatment facility completing DA Form 2173. and continues the appointment of an investigating officer who completes DD Form 261 adding appropriate statements and other documentation to support the investigation process.
In case if an informal investigation, authorized personnel must take the following steps:
The investigation will then collect evidence, reaffirm dates, events, and contacts to provide the authorities with an accurate outline of the incident that is being investigated.
Item 30 on DA Form 2173 should be left blank by the unit commander if a formal LD investigation is needed or demanded. The unit commander, however, is required to enter the reason for the formal LD investigation.
Line-by-line instructions and an explanation of all related actions can be found in Army Regulation 600–8–4, Line of Duty Policy, Procedures, and Investigations.