Ca Medical Assn is located at 221 Main St # 560, San Francisco, CA. This location is in the South Beach neighborhood.. Ca Medical Assn is open Mon, 9am-5pm; Tue, 9am-5pm; Wed, 9am-5pm; Thu, 9am-5pm; Fri, 9am-5pm; Sat, Closed; Sun, Closed and accepts Mastercard and Visa.