Student Loan Fairness Act This bill addresses repayment plans, forgiveness, and applicable interest rates for student loans. Among other things, the bill establishes an income-based 10/10 Loan Repayment Plan and specifies the calculation of monthly loan payments under the plan for borrowers of Federal Family Education Loans (FFELs) and Direct Loans; establishes a 10/10 Loan Forgiveness Program that provides FFEL and Direct Loan forgiveness to borrowers who, over 10 years, have made 120 monthly payments under the 10/10 Loan Repayment Plan or under another repayment plan that required them to make payments at least as large as those they would have made under the 10/10 Loan Repayment Plan; caps the interest rate on new Direct Loans at 3.4%; revises the Public Service Loan Forgiveness (PSLF) program to forgive the Direct Loans of participants who have made 60 (rather than 120) monthly payments on such loans pursuant to specified repayment plans; includes primary care physicians in medically underserved areas in the PSLF program; allows certain borrowers to consolidate their private education loans as Direct Consolidation Loans; directs the Consumer Financial Protection Bureau to issue regulations that require private education lenders to sell private education loans to the Department of Education (ED) for consolidation as Direct Consolidation Loans; and requires ED to pay the interest that accrues on certain student loans due to the borrower's lack of full-time employment for an interest-free deferment period of up to three years.