Source: Federal Reserve Bank of Philadelphia  

Release: FR Y-14M Large Bank Credit Card and Mortgage Data  

Units:  Percent, Not Seasonally Adjusted

Frequency:  Quarterly, End of Quarter

The annualized net charge-off rate for all credit card accounts. Net charge-offs refer to the three-month sum of gross charge-offs less recoveries. The annualized net charge-off rate is calculated as four times the total quarterly net charge-offs divided by the three-month average for total outstanding credit card balances.

For more detail see the methodology.