Today the system of supplementary professional education (SPE) is the main institutionalized subunit that is oriented toward "adult learners". Surveys have shown that in many cases investment in SPE is more profitable, predictable, reliable, and short term than that in any other form of education. Data on supplemental professional education in Russia indicate that in the future it will be increasingly provided by private companies and independent educational institutions rather than by state-funded organizations. This article discusses the characteristics and forms of activity of institutions offering SPE. It also discusses the effectiveness of the corporate sector of supplementary education. The author stresses that it is possible to envision the ways that supplementary professional education in Russia is likely to develop further and become institutionalized. (Contains 1 table and 5 notes.)