US Post Office is located at 110 E 3Rd St, Onsted, MI. This business specializes in Post Offices. US Post Office is open Mon, 9am-3:25pm; Tue, 9am-3:25pm; Wed, 9am-3:25pm; Thu, 9am-3:25pm; Fri, 9am-3:25pm; Sat, 8:05am-10:05am; Sun, Closed and accepts American Express, Discover, Mastercard and Visa.