Eligibility requirements for graduate school grants can vary considerably based on the type and source of the grant. They can also fluctuate based on the degree you seek and what you plan to study. Need based grants are awarded almost entirely on your income and amount of unmet financial need, which will need to be documented thoroughly when you apply. Research grants awarded at the doctoral level are based almost entirely on academic and professional qualifications. For example, the HUD Doctoral Dissertation Research Grant is available only to doctoral candidates pursuing policy-relevant research issues who are also receiving substantial support from their institution.