The Screen for Cognitive Impairment in Psychiatry is a simple, fast, and easy to administer scale that has been validated in clinical and community samples. The aim of this study was to propose a polytomous scoring system for the Screen for Cognitive Impairment in Psychiatry and to demonstrate its functioning, thus providing new and complementary information regarding the utility and precision of this screening tool. Three hundred seventy-six Spanish patients diagnosed with schizophrenia spectrum disorder were evaluated. A polytomous scoring system was generated and analyzed by means of the partial credit model. Category assessment revealed optimal functioning after collapsing the 7-category system to 1 with either 5 or 4 categories, depending on the item. The proposed polytomous scoring system shows good psychometric properties and an adequate fit to the partial credit model. These results provide further confirmation of the test's utility in clinical settings and of its suitability for detecting cognitive impairment.