The federal financial aid limit for graduate students is $138,500 and no more than $65,500 of this may be in subsidized loans. If you are looking for additional financial aid you should apply for the GradPlus loan
http://www.gradloans.com/graduate-plus-loan/. This loan is federal but does not count towards your cap. It is based on credit, but looks at your credit history not your credit rating so you will have a good chance of getting it.