A study examined the effect that increased high school graduation requirements are having on Colorado vocational enrollments and explored products and models for educators in school districts to use in minimizing any such adverse effects on enrollment. The study entailed a literature review, a survey of state high school science and mathematics supervisors, and examination of curriculum guides from various states to identify common mathematics and science skills. Next, 13 occupational courses were used to illustrate how the identified list of suggested skills can be coded to highlight the many essential skills that can and are being taught through vocational courses. A set of models was developed, and recommendations were made for local school districts working to minimize adverse effects of increased graduation requirements on vocational enrollments. The five models developed revolved around the following accreditation options: offering direct credit for vocational courses; awarding shared credits for vocational courses; competency testing in lieu of credits required; requesting policy changes at the local district level to reduce established credit requirements based on coded skills, tests, demonstrated occupational needs of students, and national and state trends; and adopting or adapting a successful model from exemplary programs in other districts. (Appendixes to this report include a review of related literature, a state science and mathematics survey, suggested criterion-referenced tests of essential skills, and codings of science and mathematics to suggested essential skills included in vocational courses.) (MN)