The ARC ELM is a top-down expected credit loss system that projects the intertemporal effects of both loan default cycles and macroeconomic conditions on credit losses for U.S. banks. The ARC ELM is based on an Ordinary Least Squares (OLS) time series analysis using historical loan loss and macroeconomic data, while, importantly, also maintaining certain assumptions about loan portfolio management, loan loss transitioning, and loan loss provisioning, among other factors. This system is used to calculate the life of loan expected credit losses while explicitly managing the time delays between non-accrual, gross charge-off, and recovery. The ARC ELM provides a long-run credit loss curve that enables U.S. banks to properly calculate the required Current Expected Credit Loss Allowance (“CECL Allowance”) in compliance with ASU 2016-13. In this paper, we use the Federal Deposit Insurance Corporation (FDIC) aggregate public data for Real Estate Loans Secured by 1-4 Family Residential Properties as an example to derive an expected loss curve and a CECL Allowance using the ARC ELM System.