James F. Perna has practiced law in Washington DC for over 40 years, specializing in tax, real estate finance, corporate, partnership, and investment matters. His clients include banks, mutual funds, insurance companies, mortgage bankers, tax-exempt organizations, real estate developers, holding companies, entrepreneurs, commercial enterprises, and foreign investors. He also advises on estate planning and tax strategies for individuals. Mr. Perna has performed legal services for tax syndications, tax-exempt bond issues, securitizations, work-outs, and bankruptcies. Mr. Perna has counseled and advised such matters as capital formation, equity terms, stock options, securitization of debt, and executive compensation, in addition to strategies and analysis on investor and lender negotiations, mergers, spin-offs, and acquisitions, leasing, and business contract issues.

In CIC Services LLC vs IRS, 141 S.Ct. 1582 (2021), Mr. Perna assisted in developing the legal arguments which the US Supreme Court determined to be persuasive in a 9-0 victory to Mr. Perna's client, CIC Services,  reversing prior case law  and ruling against the IRS.