[en] The absorbed radiation dose from internal emitters has been and will remain a pivotal factor in assessing risk and therapeutic utility in selecting radiopharmaceuticals for diagnosis and treatment. Although direct measurements of absorbed dose and dose distributions in vivo have been and will continue to be made in limited situations, the measurement of the biodistribution and clearance of radiopharmaceuticals in human subjects and the use of this data in the MIRD schema is likely to remain the primary means to approach the calculation and estimation of absorbed dose from internal emitters over the next decade. Since several approximations are used in these schema to calculate dose, attention must be given to inspecting and improving the application of this dosimetric method as better techniques are developed. Problems limiting this dosimetric approach have included poor availability of human radiopharmaceutical distribution and clearance data for different radiopharmaceutical, limited access to nuclear decay data in suitable format for absorbed dose calculations for some radionuclides, dosimetric models that do not provide for nonuniform distribution of the radionuclides in tissues and organs or for dynamic changes in size and shape of some anatomic structures, and a lack of adequate source and target regions such as blood and gall bladder, dosimetric models of the various stages of pregnancy and pediatric age groups, and the S value tables for these phantoms and target structures. Pending solutions to these problems include the use of conjugate counting and tomographic imaging methods for biologic data collection, the publication of a new MIRD monograph of radionuclide decay data and decay schemes with dosimetric data for 242 radionuclides of interest to the nuclear medicine community, the development of new mathematical models for selected organs, and body phantoms, and the planned expansion of the MIRD S value tables