Senior Associate
Complex Commercial Litigation
Mackenzie is a commercial litigator with a focus on antitrust litigation, including business-to-business disputes and class actions. She also has experience in a range of commercial disputes, including cases involving securities, contract, and tort claims. She has represented both plaintiffs and defendants in state and federal litigations.
Mackenzie also maintains an active pro bono practice, often representing incarcerated people who have been denied parole in appeals to the Parole Board and, if unsuccessful, filing Article 78 petitions on their behalf in New York state courts.
The following is a list of representative matters in which Mackenzie has assisted.
Representing multiple prominent healthcare providers in antitrust claims against MultiPlan, Inc. and alleged co-conspirators for underpaying out-of-network reimbursements
Representing State Street Corporation in lawsuit brought by 13 state attorneys general concerning alleged conspiracy to cut coal production
Representing companies providing real estate services in a class action alleging price-fixing of brokers’ commissions in coordination with a trade association
Representing a property management company in a class action alleging the existence of a conspiracy to increase the price of apartments using a common algorithm
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Client Alerts
SCOTUS Unanimously Resolves Securities Fraud Circuit Split
On April 12, 2024, the U.S. Supreme Court unanimously held that, in the absence of an otherwise misleading statement, a failure to disclose information required by Item 303 of Regulation S-K (“Item 303”[i]) does not support a private action under Section 10(b) of the Securities and Exchange Act of 1934 (“Section 10(b)”).
April 17, 2024
April 17, 2024 • 4-minute read
Client Alerts
On March 5, 2024, the White House announced the establishment of a new “Strike Force on Unfair and Illegal Pricing” …
March 26, 2024 • V&E Antitrust Update
March 26, 2024 • 6-minute read
Client Alerts
Item 303 Circuit Split to be Heard in the Next SCOTUS Term
On September 29, 2023, the U.S. Supreme Court agreed to weigh in on the validity of a familiar allegation in private securities litigation—that a failure to disclose under Item 303 of Regulation S-K (“Item 303”) supports a claim of securities fraud.
October 6, 2023
October 6, 2023 • 5-minute read
Awards & Rankings
The Best Lawyers in America (BL Rankings, LLC) has named 125 Vinson & Elkins lawyers in its “Best Lawyers” category in the 2026 edition. Additionally, 76 Vinson & Elkins attorneys have been named in the “Ones to Watch” category, which recognizes lawyers with 5–10 years’ experience. Some individuals are listed in more than one practice area, giving the firm a total of 305 rankings.
August 21, 2025
August 21, 2025 • 3-minute read
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