Which entity is responsible for filling out form 3346?

Form 3346, also known as the "Application for a Social Security Number" specifically for individuals applying for benefits under the Social Security Administration, is indeed filled out by the Social Security Administration (SSA). This form is utilized to collect necessary personal information from individuals who need to establish or update their records with the SSA.

The SSA is the federal agency responsible for administering the social security program in the United States, which includes managing benefits for retirees, disabled individuals, and survivors. Since the form is designated for use in the context of Social Security numbers, it falls within the purview of this agency.

Other entities like USPS, FEMA, and the Department of State are involved in different functions within the federal government but do not handle the specific processes related to Social Security numbers and benefits. This makes the SSA the appropriate choice for filling out form 3346.