Who is responsible for filling out the DD Form 2138 for a dependent over the age of 18 when an active duty sponsor is retiring?

The correct answer focuses on the fact that it is the dependent who is responsible for filling out the DD Form 2138 when an active duty sponsor is retiring. This form, often used for documenting eligibility for continued health care benefits, specifically requires input from the dependent to accurately reflect their information and circumstances.

Having the dependent complete the form ensures that the details provided are accurate and in line with their understanding of their own status, which is crucial for benefits determinations. This autonomy also aligns with the responsibility of older dependents, as those over the age of 18 are typically expected to manage their own affairs, including documentation related to their benefits.

In contrast, the sponsor might not have the most current or relevant information about the dependent's status, especially if they are transitioning through a period of retirement. Similarly, a health administrator or an independent guardian would not have the requisite personal knowledge about the dependent's situation to complete the form accurately as the dependent would. Therefore, the inherent responsibility for this documentation lies with the dependent themselves.