For more than 25 years, Ann Coffin's practice has focused on the representation of natural gas pipeline, natural gas distribution, electric, water, and telecommunications utilities in matters before the Railroad Commission of Texas and the Public Utility Commission of Texas. Her practice encompasses a wide range of administrative areas, including utility rate change applications, gas cost recovery, and proceedings for which transactional approval or CNN authority is sought. She also advises her clients in connection with legislation and regulatory proceedings in Texas and other states.

In addition to holding positions at both the RCT and the Public Utility Commission of Texas, Ann has also successfully represented utility interests before the Texas Supreme Court and other appellate courts.

Ann is consistently recognized by peers as a leader in the state regulatory and litigation fields and by other organizations, including Chambers USA (2011-2026), U.S. News & World Report (2016-2024), and Best Lawyers in America (2011-2027), which recognized her as 2024 Lawyer of the Year for Administrative/Regulatory (Austin).