Texas. Ascension Medical Group Providence Sleep Clinic ... Ascension Medical Group Providence Sleep Clinic. Specialty Care; Address. 305 Londonderry Dr Building 3 Waco, TX 76712. Phone. 254-537-6191 Hours. Mon-Thurs: 8 a.m.-12 p.m., 1 p.m-5 p.m. Fri: 8 a.m-12 p.m., 2 p.m-5 p.m. ... The Ascension Providence Patient Portal is an online service ....