Data is needed to demonstrate that providing an 'intermediate' level of type 1 diabetes (T1D) care is cost-effective compared to 'minimal' care in less-resourced countries. We studied these care scenarios in six countries.We modelled the complications/costs/mortality/Healthy Life Years (HLYs) associated with 'intermediate' care including two blood glucose tests/day (mean HbA1c 9.0% (75 mmol/mol)) in three lower-GDP countries (Mali, Tanzania, Pakistan), or three tests/day (mean HbA1c 8.5% (69 mmol/mol)) in three higher-GDP countries (Bolivia, Sri Lanka, Azerbaijan); and compared findings to 'minimal' care (mean HbA1c 12.5% (113 mmol/mol)). A discrete time Markov illness-death model with age and calendar-year-dependent transition probabilities was developed, with inputs of 30 years (y) of complications and Standardized Mortality Rate data from the youth cohort in the Pittsburgh Epidemiology of Diabetes Complications Study, background mortality, and costs determined from international and local prices.Cumulative 30y incidences of complications were much lower for 'intermediate care' than 'minimal care': e.g. for renal failure incidence was 68.1% (HbA1c 12.5%) compared to 3.9% (9%) and 2.4% (8.5%). For Mali, Tanzania, Pakistan, Bolivia, Sri Lanka, and Azerbaijan, 30y survival was 50.1%/52.7%/76.7%/72.5%/82.8%/89.2% for 'intermediate' and 8.5%/10.1%/39.4%/25.8%/45.5%/62.1% for 'minimal' care respectively. The cost of a HLY gained as a % GDP/capita was 141.1%/110.0%/52.3%/41.8%/17.0%/15.6% respectively.Marked reductions in complications rates and mortality are achievable with 'intermediate' T1D care achieving mean clinic HbA1c of 8.5-9% (69-75 mmol/mol). This is also 'very cost-effective' in four of six countries according to the WHO 'Fair Choices' approach which costs HLYs gained against GDP/capita. This article is protected by copyright. All rights reserved.