Agree with John Burnett. The GSE Agency QM is acceptable, even with DTI > 43%, provided you receive an FNMA DU Approve Eligible or FHLMC LP Approve, and the loan is eligible for sale to the GSE. It is not required the loan be sold, just eligible for sale.
Jumbo loans that are not GSE eligible would not have this QM option if the DTI is >43% and these are considered Non-QM, without any type of safe harbor.
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Old School Banker