Dependability is a non-functional property that should be assessed early in the software lifecycle. Although several UML profiles exist for quantitative annotations of non-functional properties, none of them provides concrete capabilities for dependability analysis of UML system models. In this paper, we propose a dependability analysis and modeling profile. The objective is twofold: to reuse proposals from the literature on deriving dependability models from UML annotated specifications and to be compliant with the recently adopted MARTE profile, which provides a framework for general quantitative analysis concepts that can be specialized to a particular analysis domain. The profile definition process was done in several steps. Firstly, an in depth analysis of the literature has been carried out to collect the information requirements for the profile. Secondly, a domain model for dependability analysis was defined independently of UML. Thirdly, the domain model was mapped to UML extensions by specializing MARTE.