Every technology the IRS has classified, drawn as its two compliance branches: structural Steel/Iron items (an absolute, pass/fail test) and Manufactured Products, whose Manufactured Product Components carry the assigned cost percentages summed against the adjusted-percentage threshold.
† Production is the cost of manufacturing the parent product itself; it counts only if every listed MPC of that product is domestically produced (Notice 2023-38 §3.03(2)).
Under the elective safe harbor the listed items are exclusive and exhaustive: a listed item that is absent or foreign counts as zero, and unlisted items are disregarded. Solar variants labeled “+ domestic wafers” may be used only when the modules incorporate c-Si cells made from U.S.-manufactured wafers.
Offshore wind and hydropower have classification trees only — no assigned percentages exist, so their Domestic Cost Percentage must be computed from manufacturers’ actual direct costs.
The hierarchy stops at MPCs. An MPC counts as U.S.-made if it was manufactured in the United States “regardless of the origin of its subcomponents” (Notice 2023-38 §3.03, adopting 49 CFR 661.5(d)). A blade molded and cured at a U.S. plant from imported fiberglass and resin is a U.S. MPC at its full percentage; an imported blade made of American materials is foreign.