This matches January as the lowest delinquency rate since November 2007.
Freddie's serious delinquency rate peaked in February 2010 at 4.20%.
These are mortgage loans that are "three monthly payments or more past due or in foreclosure".
This is close to a cycle bottom. However, with COVID-19, this rate will probably increase in a few months (it takes time since these are mortgage three months or more past due).
Note: Fannie Mae will report for February soon.