License Requirements
| State | Licensing Requirements | Certifications | Education | Comments |
| Ohio | Master (Owners) only | EPA | Various Exams | https://www.com.ohio.gov/dico/ocilb/LicenseQualificationProcess.aspx |
| Indiana | Master (Owners) only | EPA | Low Requirements | https://www.hvaccertification.org/hvac-license-indiana/ |
| Kentucky | Journeyman & Masters | EPA | Strict | https://www.hvaccertification.org/kentucky-hvac-license/ |
| Michigan | Varies By City | Varies By City | Various Exams | https://www.hvaccertification.org/michigan-hvac-license/ |
| West Virginia | Master (Owners) only | Various Needed | Various Exams | https://labor.wv.gov/Licensing/HVAC/Pages/hvac-faq.aspx |
| Pennsylvania | Varies By City | Varies By City | Various Exams | https://www.hvaccertification.org/pennsylvania-hvac-license/ |
| Tennessee | Master (Owners) only | EPA | Lenient | https://www.tn.gov/commerce/regboards/contractor/license-requirements.html |