The LA Times reports that Lerner will refuse to answer any questions about what she knows about the targeting of conservative groups. She will also refuse to explain why she is refusing to answer questions.
Lerner has retained defense attorney William W. Taylor 3rd, who sent a letter to Darrell Issa, the Chairman of the House Oversight Committee. In the letter Taylor said, "She has not committed any crime or made any misrepresentation but under the circumstances she has no choice but to take this course.”
Taylor is hoping Issa will excuse his client from having to testify in order to save her the embarrassment of having to invoke the Fifth in public. Per The L.A. Times, the committee hasn't yet answered her request one way or the other.
ADDED: National Journal reports that Issa "has issued a subpoena to Lerner anyway."