[en] The calculation of beta ray dose to the skin due to I-131 contamination includes some assumptions that leads to uncertainties in the evaluation. Because of uncertainties in isotope distribution, two methods have been employed using: (a) the thin infinite-plane source model of Loevinger, et al, and (b) the MIRD model using the S factors for electrons and beta rays. The thin-plane source model has been applied to the case of a surface-plane source distribution realizing that there will be an error due to surface boundary effects. This model has been compared to the MIRD method which overestimates the dose to the skin (i.e., the assumption made in the calculation is that all the beta ray energy is absorbed, which is not the actual case). The surface-plane source calculation has been extended to a homogeneous distribution by assuming uniformly distributed thin-plane sources throughout the skin volume. The data indicate close agreement with the MIRD model. In addition, exponential distributions have been calculated which approach the surface boundary case for large absorption rate constants. The point source data of Berger is presently being investigated to determine whether it can be extended to a plane source geometry for an additional comparison