We present the development and validation of a construct map addressing introductory quantum mechanics topics at the high school level, as a subset of a larger learning progression on quantum mechanics. Topics include energy quantization, photon absorption and emission, the Heisenberg uncertainty principle, atom stability, orbitals, wave function, and electronic properties of materials. To validate the hypothesized construct map, we designed a multiple-choice questionnaire and a 14-h teaching-learning sequence (TLS) designed in strict relation with the levels of the construct map. Twenty-three classes of Italian students (ages 17-18, N = 408) were involved in the study: about half (N = 200) were exposed to the TLS, while N = 208 students received a typical textbook instruction on the same topics targeted by the construct map. Data were analyzed using a 1D Rasch model. Results show that the proposed construct map consistently describes the increasing abilities of students when exposed to instruction. In particular, when exposed to the TLS activities, students more likely move towards the upper levels of the construct map. Findings have implications for instruction designed to support students' learning in quantum mechanics at the high school level.