Little is known about the effects of the Chronic Care Model (CCM) and community health workers (CHWs) on pharmacotherapy of type 2 diabetes and hypertension in resource-poor settings. This retrospective cohort implementation study evaluated the effects of a community-based program consisting of CCM, CHWs, guidelines-based treatment protocols, and inexpensive freely accessible medications on type 2 diabetes and hypertension pharmacotherapy quality. A door-to-door household survey identified 856 adults 35 years of age and older living in a low-income Peruvian community, of whom 83% participated in screening for diabetes and hypertension. Patients with confirmed type 2 diabetes and/or hypertension participated in the program's weekly to monthly visits for < = 27 months. The program was implemented as two care periods employed sequentially. During home care, CHWs made weekly home visits and a physician made treatment decisions remotely. During subsequent clinic care, a physician attended patients in a centralized clinic. The study compared the effects of program (pre- versus post-) (N = 262 observations), and home versus clinic care periods (N = 211 observations) on standards of treatment with hypoglycemic and antihypertensive agents, angiotensin converting enzyme inhibitors, and low-dose aspirin. During the program, 80% and 50% achieved hypoglycemic and antihypertensive standards, respectively, compared to 35% and 8% prior to the program, RRs 2.29 (1.72-3.04, p <0.001) and 6.64 (3.17-13.9, p<0.001). Achievement of treatment standards was not improved by clinic compared to home care (RRs 1.0 +/- 0.08). In both care periods, longer retention in care (>50% of allowable time) was associated with achievement of all treatment standards. 85% compared to 56% achieved the hypoglycemic treatment standard with longer and shorter retention, respectively, RR 1.52 (1.13-2.06, p<0.001); 56% compared to 27% achieved the antihypertensive standard, RR 2.11 (1.29-3.45, p<0.001). In a dose-dependent manner, the community-based program was associated with improved guidelines-based pharmacotherapy of type 2 diabetes and hypertension., Competing Interests: The authors have declared that no competing interest exist., (Copyright: © 2024 Deaver et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)