The Psychosocial Care Center for treating alcohol and drug misuse (CAPS-ad II) is a Brazilian community mental health service addressed for caring people with substance-related disorders. Financial resources are partially funded by the National government. However, CAPS´s total costs are not available for economic evaluation studies and for planning services. Despite systematic claims by CAPS´s managers for increasing reimbursement by the National Government, there is no data available showing if reimbursement covers CAPS´s total costs. OBJECTIVES::  To estimate the total costs of CAPS-ad II in a small city in the State of Sao Paulo, and to verify the proportion of CAPS´s total costs due to National reimbursements. METHODS::  This is costs analysis study with retrospective design, adopting public health provider´s perspective. Costs data were extracted from service database for a 180 days period, from March 1st to August 30th, 2015. Total costs included the following component of costs: human resources, support services, capital costs, and overhead. Medication costs were not included. Unit costs were estimated using top down approach. RESULTS::  CAPS-ad II total cost for a 180 days period was BRL 308.167,14. Human resources accounted for 70.3% (BRL 216.918,66) of total costs; support services for 14.2% (BRL 43,883. 92), capital costs for 2.2% (BRL 6.826,68), and overhead for 13.1% (BRL 40.537,88). In 2015, National reimbursement for CAPS-ad II was 77.4% (BRL 238.680,00) of the CAPS-ad II total costs for a 180 days period. CONCLUSIONS:: Considering the fact that many small cities depend exclusively on the National Government funding, our results showed that reimbursement policy has not been sufficient for covering CAPS-ad II full total costs.