OHFA 4 Teachers Program OHFA 4 Teachers is exclusive to educators who are first time home buyers. The low interest rate program offers a Oklahoma down payment grant of 3.5 percent of the loan amount. The maximum purchase price is $214,925. A Oklahoma borrower must have an Oklahoma teachers certificate and be employed at any Oklahoma public school district or accredited private or parochial school. Other employees of the school system whose jobs require certification may also be eligible.