Budget Justifications are an important component of the proposal that: 

• Highlight, explain and provide the rationale for each budget line item.
• Include employees’ project roles, tasks they will perform and the percentage of effort required. 
• Follow the order of the detailed budget.
• Conform to the sponsor’s requirements. 

In general, all budget items should be fully detailed and explained in a proposal’s budget justification. However, there are some exceptions, such as NIH’s modular budget mechanism.