The citizen's allowance is defined by the legislator as a so-called "subordinate" social benefit.
This means that citizen's allowance is only paid if there are no other so-called priority benefit claims.

Priority benefits are payments from other agencies or institutions that are suitable for avoiding, eliminating, shortening or reducing your need for assistance from the Jobcenter.
You must claim these benefits. You must submit the necessary applications yourself.

Here are some examples of priority benefits:

• Kinderzuschlag, housing benefit, child benefit, maternity benefit, parental benefit, maintenance/advance maintenance payments,
• training and employment promotion benefits: unemployment benefit, vocational training allowance (BAB), benefits under the Federal Training Assistance Act (BAföG),
• health insurance benefits: Sickness benefit, medical rehabilitation benefits,
• Benefits from statutory accident insurance: injury benefit, pension due to reduced earning capacity,
• Benefits from statutory pension insurance: transitional allowance, old-age pension, pensions due to partial or full reduction in earning capacity, survivors' pension.

You can find a comprehensive overview of priority benefits and further information on the website of the Federal Employment Agency.