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Katherine Mayer

Katherine Mayer

also known as Kate Mangan, Kate Mayer Mangan

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About me

I handle civil appeals in the California Courts of Appeal and in the Ninth Circuit Court of Appeals.  I have significant appellate experience, including a clerkship on the Ninth Circuit Court of Appeals, experience in en banc proceedings, writs, and other appeals.  I have particular expertise in high stakes business litigation and matters involving public entities.   


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Practice areas


  1. Appeals: 100%



Fixed (sometimes)

Attorney endorsements

5 total 

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  • Sarah Levien Shullman

    Katherine is one of the most intelligent and hard-working attorneys I have ever met. After graduating at the very top of our class at Georgetown University Law Center and editing the Law Review, Katherine clerked for the prestigious Ninth Circuit Court of Appeals and worked for a preeminent law firm in California. Now the managing partner of Mayer Mangan, PLC, Katherine provides her clients with unparalleled legal services in civil appeals matters. If there is a difficult or complex legal issue, especially in the most high-stakes appeals, Katherine powerfully utilizes her legal acumen to cut through the complexities and successfully advocate for her clients' positions. Her clients could not possibly be in better hands and I highly recommend her.


    Sarah Shullman Government Attorney
    Relationship: Fellow lawyer in community

  • Colleen Carlton Smith

    I worked with Kate for many years while at Latham & Watkins on several significant appellate matters. Kate is among the most talented appellate attorneys in California. I would (and do) trust her with high-stakes appeals.


    Colleen Smith Litigation Attorney
    Relationship: Worked together on matter

Contact info

Mayer Mangan, PLC

10755 Scripps Poway Parkway
Suite 367
San Diego, CA, 92131


We have not found any instances of professional misconduct for this lawyer.
Avvo contributions
Legal answers
Award nameGrantorDate granted
Top Young AttorneysSan Diego Daily Transcript2011
Women Who Mean Business FinalistSan Diego Business Journal2011
Wiley W. Manuel Award for Pro Bono Legal ServicesState Bar of California2011
Wiley W. Manuel Award for Pro Bono Legal ServicesState Bar of California2010
Top Young AttorneysSan Diego Daily Transcript2008
Work experience
TitleCompany nameDuration
Founder & Adjunct Professor, Appellate Litigation ClinicUniversity Of San Diego School Of Law2009 - 2010
AssociateLatham & Watkins, LLP2006 - 2011
Trial AttorneyUs Department Of Justice2005 - 2006
ClerkU.S. Court of Appeals for the Ninth Circuit2004 - 2005
Association namePosition nameDuration
Appellate Court Committee, San Diego County Bar AssociationChair2012 - Present
Federal Bar Association of San DiegoMember, Executive Committee2009 - 2010
Louis M. Welsh American Inn of CourtAlumni Member2008 - Present
Lawyers Club of San DiegoMember2006 - Present
Legal cases
Case nameOutcome
Border Business Park v. City of San DiegoPending
Young v. HolderN/A
Czajkowski v. Haskell & White, LLPN/A
See all legal cases 
Publication nameTitleDate
San Diego ABTL ReportMaking the Record: Appellate Hints for Trial Lawyers2012
Federal Bar Association newsletter, San Diego chapterHow to Effectively Use Contract Attorneys to Build Your Practice2011
Federal Bar Association newsletter, San Diego chapterThe Ninth Circuit Formulates a 'New' Abuse of Discretion Standard of Review2010
San Diego Daily TranscriptAppellate Attorneys: Why Hire Them and How to Choose Them2009
Georgetown Law JournalAn Unjust War: The Case Against the Government's War on Obesity2005
School nameMajorDegreeGraduated
Georgetown University Law CenterLawJD - Juris Doctor2004
Pomona College (Claremont)N/ABA - Bachelor of Arts2000
Speaking engagements
Conference nameTitleDate
San Diego City Attorneys Office SeminarHow to Win an Appeal2008