This paper presents a maturity model of IT service delivery that consists of maturity statements grouped on five maturity levels. The model is founded on maturity model properties and IT Capability Maturity Model (IT Service CMM). It was motivated by the interest and limitation of Nicaraguan Internet Service Providers in formalizing and assessing specific IT service elements. The model was applied to traceable information of the current status of IT service delivery in a Nicaraguan Internet Service Provider.