Page 1 of 176
Missouri (St. Louis County) Commercial
HVAC Servicer/Installer - 588-MO-SL
Contractor Practice Exam -Questions with
Correct Answers and Explanations.
Q1. As of 2026, which of the following statements best describes
HVAC licensing requirements in Missouri?
A) The state issues a single statewide HVAC contractor license
through the Division of Professional Registration
B) HVAC licensing is administered at the local municipal/county
level, with no statewide HVAC license
C) Only the City of St. Louis requires HVAC licensing, while
counties have no requirements
D) Missouri requires both a state license and a separate county
license for all HVAC work
,Page 2 of 176
Correct Answer: B
Rationale: Missouri does not issue statewide HVAC contractor
licenses. Unlike electrical contracting (which has state-level
licensing), HVAC licensing is handled by individual cities and
counties. St. Louis County has its own Board of Examiners for
Mechanical Licensing that administers local licensing
requirements.
Q2. The proposed Missouri Statewide Mechanical Contractors
Licensing Act would have done which of the following?
A) Eliminate all local HVAC licensing requirements entirely
B) Create a statewide mechanical contractor license while
allowing local jurisdictions to enforce their own codes
C) Require all HVAC contractors to work under state-employed
inspectors
D) Remove insurance requirements for mechanical contractors
,Page 3 of 176
Correct Answer: B
Rationale: Proposed bills SB392 and HB547 (2025 session)
would have established the Missouri Statewide Mechanical
Contractors Licensing Act, creating statewide licenses for
mechanical contractors, journeymen, and apprentices. However,
these bills did not pass as of 2026. Under the proposed system,
political subdivisions would have been required to recognize
statewide licenses but could still enforce their own codes and
inspect work.
Q3. In St. Louis County, how many continuing education hours are
required to renew an HVAC/mechanical contractor license?
A) 8 hours every year
B) 12 hours every 2 years
C) 24 hours (12 PEUs) every 3 years
D) 40 hours every 5 years
, Page 4 of 176
Correct Answer: C
Rationale: St. Louis County requires 24 hours (12 Professional
Education Units/PEUs) of approved continuing education every 3
years. At least 6 hours must be in core topics and at least 6 hours
in trade topics. The course material must be approved by the
Board of Examiners for Mechanical Licensing.
Q4. A St. Louis County HVAC contractor license renewal requires
completion of continuing education credits approved by which
entity?
A) Missouri Division of Professional Registration
B) International Code Council (ICC)
C) Board of Examiners for Mechanical Licensing
D) St. Louis County Department of Revenue
Correct Answer: C
Missouri (St. Louis County) Commercial
HVAC Servicer/Installer - 588-MO-SL
Contractor Practice Exam -Questions with
Correct Answers and Explanations.
Q1. As of 2026, which of the following statements best describes
HVAC licensing requirements in Missouri?
A) The state issues a single statewide HVAC contractor license
through the Division of Professional Registration
B) HVAC licensing is administered at the local municipal/county
level, with no statewide HVAC license
C) Only the City of St. Louis requires HVAC licensing, while
counties have no requirements
D) Missouri requires both a state license and a separate county
license for all HVAC work
,Page 2 of 176
Correct Answer: B
Rationale: Missouri does not issue statewide HVAC contractor
licenses. Unlike electrical contracting (which has state-level
licensing), HVAC licensing is handled by individual cities and
counties. St. Louis County has its own Board of Examiners for
Mechanical Licensing that administers local licensing
requirements.
Q2. The proposed Missouri Statewide Mechanical Contractors
Licensing Act would have done which of the following?
A) Eliminate all local HVAC licensing requirements entirely
B) Create a statewide mechanical contractor license while
allowing local jurisdictions to enforce their own codes
C) Require all HVAC contractors to work under state-employed
inspectors
D) Remove insurance requirements for mechanical contractors
,Page 3 of 176
Correct Answer: B
Rationale: Proposed bills SB392 and HB547 (2025 session)
would have established the Missouri Statewide Mechanical
Contractors Licensing Act, creating statewide licenses for
mechanical contractors, journeymen, and apprentices. However,
these bills did not pass as of 2026. Under the proposed system,
political subdivisions would have been required to recognize
statewide licenses but could still enforce their own codes and
inspect work.
Q3. In St. Louis County, how many continuing education hours are
required to renew an HVAC/mechanical contractor license?
A) 8 hours every year
B) 12 hours every 2 years
C) 24 hours (12 PEUs) every 3 years
D) 40 hours every 5 years
, Page 4 of 176
Correct Answer: C
Rationale: St. Louis County requires 24 hours (12 Professional
Education Units/PEUs) of approved continuing education every 3
years. At least 6 hours must be in core topics and at least 6 hours
in trade topics. The course material must be approved by the
Board of Examiners for Mechanical Licensing.
Q4. A St. Louis County HVAC contractor license renewal requires
completion of continuing education credits approved by which
entity?
A) Missouri Division of Professional Registration
B) International Code Council (ICC)
C) Board of Examiners for Mechanical Licensing
D) St. Louis County Department of Revenue
Correct Answer: C
