Qualified progress expenditures.
(6) Qualified progress expenditures. For progress expenditure property that is constructed, reconstructed, or erected by the taxpayer within the meaning of 1.48-2(b), the ten-percent credit applies in the year the property is placed in service to the portion of the qualified investment that remains after reduction for qualified progress expenditures under section 46(c)(4), but only to the extent that the remaining qualified investment is attributable to construction, reconstruction, or erection after January 21, 1975. For progress expenditure property that is acquired by the taxpayer (within the meaning of 1.48-2(b)) after January 21, 1975, and placed in service after that date, the ten-percent credit applies in the year the property is placed in service to the entire portion of qualified investment that remains after reduction for qualified progress expenditures.