MD. Endocrinology & Diabetes. (303) 666-2640. (303) 541-0807 (Fax) 4745 Arapahoe Ave., Suite 200, Boulder, CO 80303. Important Notice: Dr. Lerner's clinic is now located at Boulder Medical Center-Foothills. The new address is 4745 Arapahoe Ave, Suite 200 in Boulder..