A Monte Carlo model with special features for modeling of radiation transport through very thin layers has been presented. Over the decades traditional Monte Carlo model has been used to model highly scattering thin layers in skin and may inaccurately capture the effect of thin layers since their interfaces are not perfectly planar and thicknesses non-uniform. If the Monte Carlo model is implemented without special features then the results of the simulation would show no effect of the outer thin layer since the path length of most photons would be significantly larger than the layer thickness and the resulting predicted photon travel would simply not notice the presence of the layer. Examples of multi-layered media are considered where the effect of a very thin absorbing layers is systematically examined using both the traditional Monte Carlo and that with new features incorporated. The results have profound implications in the diagnostic and therapeutic applications of laser in biomedicine and surgery.