Who counts as a contractor and what contracting means

engaging in the business of contracting to erect, construct, repair, or improve buildings or structures, of any kind or description, including any portion thereof, or to make any installation therein, or to make, construct, repair, or improve any highway, road, street, sidewalk, ditch, excavation, fill, bridge, shaft, well, culvert, sewer, water system, drainage system, dredging or harbor improvement project, electric or steam rail, lighting or power system, transmission line, tower, dock, wharf, or other improvements; (2) Every person engaging in the practice of architecture, professional engineering, land surveying, and landscape architecture, as defined in section 464-1; and (3) Every person engaged in the practice of pest control or fumigation as a pest control operator as defined in section 460J-1. "Federal cost-plus contractor" means a contractor having a contract with the United States or an instrumentality thereof, excluding national banks, where, by the terms of the contract, the United States or such instrumentality, excluding national banks, agrees to reimburse the contractor for the cost of material, plant, or equipment used in the performance of the contract and for taxes which the contractor may be required to pay with respect to such material, plant, or equipment, whether the contractor's profit is computed in the form of a fixed fee or on a percentage basis; and also means a subcontractor under such a contract, who also operates on a cost-plus basis.