rate_mod_start_date

The date when the interest type was modified under an arrears arrangement. A loan arrears arrangement or modification refers to a situation where a lender and borrower agree to adjust the terms of an existing loan due to the borrower’s difficulty in making scheduled repayments. This typically occurs after the borrower falls behind, enters arrears, or anticipates they soon will.

For additional details refer to: https://www.federalreserve.gov/apps/reportingforms/Report/Index/FR_Y-14M