Non-routine litigation must be reported to Fannie Mae within two business days of the servicer receiving notice of the litigation, except with respect to the following three categories of loan-level challenges:
a challenge to the standing of the servicer to conduct foreclosures or bankruptcies that, if successful, could create negative legal precedent with an impact beyond the immediate case;
a challenge to the methods by which MERS does business or its ability to act as nominee under a mortgage; or
any claim invoking HAMP as a basis to challenge a foreclosure.
With respect to these three categories of loan-level challenges, it is not necessary for the servicer to notify Fannie Mae until
the borrower seeks summary judgment on such a challenge,
briefing is required in response to such a challenge, or
the issue is expected to be raised at a scheduled trial.
Additional Information: https://www.fanniemae.com/content/guide/servicing/e/1.3/02.html