My partner has worked in HVAC for many years and is now pursuing his journeyman's license, which requires hours worked under a licensed HVAC professional. The process for obtaining a journeyman's license in Baltimore involves applying to the state's apprenticeship program, which combines on-the-job training over 4-12 months with biweekly evening classes. Apprentices earn a percentage of a journeyperson's salary that increases over time, up to 100% upon completion. Candidates must be at least 18 years old and pass an exam.