Pregnant heifers are undesirable in the feedyard. We applied simulation modeling to a partial-budget model to compare alternative strategies for managing pregnant heifers in feedyards. The model was developed with input costs (cattle, preventive medical care, morbidity, mortality, treatments, and performance), input benefits (sales of poorly performing heifers, baby calves, open (non-pregnant) heifers, recently calved heifers, and pregnant heifers), and net returns as the output. Predicted mean net returns for feeding either open heifers or aborted heifers were greater than $ 100 (live-basis sales) to $ 200 (rail-basis sales) higher than for pregnant heifers. However, there was substantial variability in net returns for all three types of heifers.Net returns were compared among three decision choices made upon arrival of the cattle at the feedyard: (1) palpate all heifers and inject with abortifacient only those pregnant (PALABT), (2) inject all heifers with abortifacient without determining pregnancy status (ABTALL), and (3) do not palpate or administer abortifacient to any of the heifers (NOTHING). Predicted returns for PALABT and ABTALL were equivalent when estimated pregnancy prevalence was 43% (median net returns=$44.92 and $ 50.46, respectively). For heifer lots with pregnancy prevalences =<36%, PALABT yielded higher net returns than ABTALL but the opposite was true when the pregnancy prevalence was =<49%. Net returns for PALABT and NOTHING were equivalent when the estimated prevalence of pregnancy was 2% on a live-basis sales (median net return=$50.05) and approximately 0.9% on a rail-basis sales (median net returns=$58.36 (PALABT) and $ 58.30 (NOTHING)) (with PALABT yielding positive net returns at the higher pregnancy prevalences). NOTHING yielded a positive net return relative to PALABT when the pregnancy prevalence was <1.5% (live-basis sales) and <0.5% (rail-basis sales).