Mechanical Insulation Installation Incentive Act of 2023 This bill allows a tax credit through 2028 for 10% of the labor costs of installing mechanical insulation property. The bill defines mechanical insulation property as insulation materials, and facings and accessory products placed in service in connection with a mechanical system that (1) is located in the United States; (2) meets or complies with the minimum requirements of Reference Standard 90.1 (published by the American Society of Heating, Refrigerating, and Air Conditioning Engineers and the Illuminating Engineering Society of North America); and (3) results in a reduction in energy loss from such system after its installation.