Appendix B: Explanation of Specific Occupations

Several occupations warrant greater explanation than space in the Occupation Profiles permits. Following below are further details of these occupations and how we observed them.

Contractor Occupations – Commercial and Residential

Contractor licensing regulatory schemes vary from state to state. Generally, they vary based on three factors: the setting of the work, the type of work and the minimum contract size that requires licensure. Below, we describe these factors as well as how we handled them when collecting data.

In terms of setting, some states issue different licenses for work performed in commercial and residential settings. For example, Arizona issues one concrete contractor license for residential work (“R-9 Concrete”) and another for commercial work (“C-9 Concrete”). 1  In such cases, we looked at the commercial license in the commercial contractor occupation and the residential license in the residential contractor occupation.

Other states, however, require the same license regardless of setting. Such nonspecific licenses are sometimes called general contractor licenses. For example, Idaho requires the same contractor registration regardless of whether a contractor works on residences or commercial buildings. 2  In such cases, we observed the same license in both commercial and residential contractor occupations.

States also vary in terms of how they regulate the type of work contractors do. Some states have one license that covers all types of work, while others have specialty licenses for each type of work. For example, to do commercial glazing or drywall work in Oregon, all one needs is a “Commercial Specialty Contractor Level 2” contractor license. 3  But in California, glazing and drywall work require separate licenses. For glazing work a contractor needs a “C-17 – Glazing Contractor” specialty classification, 4  while for drywall work a contractor needs a “C-9 – Drywall Contractor” specialty classification. 5  When presented with specialty licenses, we chose the least burdensome specialty to cover the type of work found in the occupation’s definition.

Finally, many contractor licenses apply only once a certain contract size (often expressed in dollars of revenue) is reached, and these minimum contract sizes vary substantially. 6  For example, the Idaho contractor registration mentioned above is required to work on contracts worth at least $2,000. 7  Meanwhile, Louisiana’s commercial contractor license applies only to contractors working jobs worth at least $50,000. 8  Our data do not factor in minimum contract sizes: If a state has a license, we count it as licensing the occupation regardless of the minimum contract size, if any, at which it applies.

Table B1 shows state regulation of settings (commercial, residential or both) for contractor licensing. It also lists the titles or types of licenses we observed as well as any minimum contract sizes (in dollars). In the title, “specialty classification” is a state-specified contractor license category that covers the type of work the contractor can perform. As described above, titles vary by contractor occupation in this report because the type of work varies.

Table B1 covers licenses for all the contractor occupations observed in this report, except for those related to HVAC systems (see Table B2), with an important caveat: For each state, it covers only the specific contractor occupations licensed by the state. For example, terrazzo contractors are not licensed by New Mexico, while other types of contractors, such as masonry and insulation, are. 9  The State Profiles indicate which contractor occupations each state licenses.

Landscape contractors often face special requirements in addition to or instead of those listed in Table B1. In addition to any contractor licenses listed in the table, landscape contractors in 14 states also need one of the following types of nursery or landscaping-related licenses in both commercial and residential settings unless otherwise noted:

  • Horticulturist license: Louisiana (commercial only) and Mississippi (commercial only).
  • Landscape contractor license: Arkansas and Idaho.
  • Landscaper license: Tennessee.
  • Nursery license: North Dakota.
  • Nursery outlet license: Utah.
  • Nursery/plant dealer license: Iowa, Maryland, Nevada, New Jersey (residential only), Washington and West Virginia.
  • Setting of landscape plants and turf/pest control licenses: Alabama (commercial only).

In 29 states, instead of any contractor licenses listed in Table B1, landscape contractors need one of the following nursery or landscaping-related licenses in both commercial and residential settings unless otherwise noted:

  • Horticulturist license: Louisiana (residential only) and Mississippi (residential only).
  • Landscape contractor business and landscape construction professional licenses: Oregon.
  • Nursery license: Colorado and Delaware.
  • Nursery dealer license: Missouri.
  • Nursery-floral license: Texas.
  • Nursery landscaper license: Oklahoma.
  • Nursery/plant dealer license: Florida, Georgia, Illinois, Indiana, Kansas, Kentucky, Maine, Michigan, Minnesota, Montana, New Hampshire, New Jersey (commercial only), New Mexico, New York, Ohio, Pennsylvania, South Dakota, Vermont, Wisconsin and Wyoming.
  • Setting of landscape plants and turf/pest control licenses: Alabama (residential only).

Licenses for the HVAC contractor and HVAC sheet metal contractor occupations are excluded from Table B1 because many of them are completely different licenses issued by different boards and subject to different contract size minimums.

Table B2 shows state regulation of settings (commercial, residential or both) for the HVAC contractor and HVAC sheet metal contractor occupations. The table also lists the titles of licenses observed, as well as any minimum contract sizes (in dollars).

Table B1: Contractor Licensing (Excluding HVAC and HVAC Sheet Metal)

StateSetting (Commercial vs. Residential)Title or Type of License(s)Min. Contract Size
AlabamaCommercialPrime contractor – specialty classifications*$50,000
AlabamaResidentialUnlimited residential home builder$10,000
AlaskaBothConstruction contractor – specialty classifications*$10,000
ArizonaCommercialContractor – specialty classifications*$1,000
ArizonaResidentialContractor – specialty classifications*$1,000
ArkansasCommercialContractor – specialty classifications*$50,000
ArkansasResidentialHome improvement contractor – specialty classifications*$2,000
CaliforniaBothContractor – specialty classifications*$500
Connecticut**CommercialMajor contractorNone
ConnecticutResidentialHome improvement contractor$200
District of ColumbiaCommercialGeneral contractor/construction manager Class E *None
District of ColumbiaResidentialHome improvement contractor and salesperson licenses*$300
FloridaBothCertified contractor – specialty classifications$2,500
Georgia***BothUtility contractor, manager and foreman licensesNone
HawaiiBothContractor – specialty classifications*$1,000
IdahoBothGeneral contractor registration*$2,000
IowaBothConstruction contractor registration*None
Louisiana****CommercialContractor – specialty classifications*$50,000
LouisianaResidentialHome improvement contractor$7,500
MarylandResidentialHome improvement contractor*None
Massachusetts*****ResidentialHome improvement contractor and construction supervisor licenses*$500
MichiganResidentialMaintenance and alteration contractor – specialty classifications$600
MississippiCommercialContractor – specialty classifications*$50,000
MississippiResidentialResidential remodeler$10,000
NebraskaBothContractor registration*None
NevadaBothContractor – specialty classifications*$1,000
New JerseyResidentialHome improvement contractor*$500
New MexicoBothGeneral construction contractor – specialty classifications$7,200
North CarolinaBothGeneral contractor – specialty classifications*$30,000
North DakotaBothGeneral contractor – Class D*$4,000
OregonCommercialCommercial specialty contractor – Level 2$1,000
OregonResidentialResidential specialty contractor$1,000
PennsylvaniaResidentialHome improvement contractor$500
Rhode IslandCommercialGeneral contractor registration$500
Rhode IslandResidentialResidential contractor registration$500
South CarolinaCommercialContractor – specialty classifications$5,000
South Carolina******ResidentialResidential contractor – specialty classification$200
TennesseeBothContractor – specialty classification*$25,000
UtahBothContractor – specialty classification*$3,000
VirginiaBothClass C contractor – specialty classification*$1,000
Washington*******BothContractor – specialty classification*$500
West VirginiaCommercialContractor – specialty classification*$25,000
West VirginiaResidentialContractor – specialty classification*$5,000
Wisconsin***BothUtility contractor registrationNone
*License applies to landscape contractors.
**In lieu of the major contractor license, commercial glazier contractors in Connecticut require specialized flat glass contractor and journeyperson licenses. The contractor license applies for jobs involving panes of glass of 30 square feet or larger.
*** These states’ licenses are required only for the pipelayer contractor occupation. All the other licenses in the table that apply in both settings or in commercial settings only—with the exception of Connecticut’s—are required for pipelayer contractors.
****In addition to the contractor license, commercial door repair contractors in Louisiana require a door hardware certificate from the state fire marshal.
*****In Massachusetts, residential cement finishing and painting contractors require only the home improvement contractor license. Also, the home improvement and construction supervisor licenses do not apply to residential non-HVAC sheet metal contractors. Instead, these contractors must have the following two licenses, regardless of setting: restricted sheet metal journeyperson and apprentice. There is no minimum contract size.
******In South Carolina, residential glazier and iron/steel contractors require a residential builder’s license, which does not encompass any specialty classifications. 
*******Though specialty classifications exist for both carpenter contractors and cabinet maker contractors in Washington, a contractor can hold only one specialty license at a time. A contractor who specializes in both carpentry and cabinet making therefore needs a general contractor license. Thus we observe that license for the carpenter/cabinet maker contractor occupation.

Table B2: HVAC and HVAC Sheet Metal Contractor Licensing

StateSetting (Commercial vs. Residential)Title of HVAC Contractor License(s)Title of HVAC Sheet Metal Contractor License(s)Min. Contract Size
AlabamaCommercialHVAC contractor certification and mechanical contractor license – HVAC subclassification(Same)Certification: None
License: $50,000
AlaskaCommercialMechanical administrator – unlimited HVAC/sheet metal category and mechanical contractor registration(Same)None
AlaskaResidentialMechanical administrator – residential HVAC category and mechanical contractor registration(Same)None
ArizonaCommercialComfort heating, ventilating, evaporative cooling specialty commercial contractor(Same)$1,000
ArizonaResidentialComfort heating, ventilating, evaporative cooling specialty dual contractor(Same)$1,000
ArkansasCommercialHVACR specialty building contractor and HVACR Class A trade licensesDuct sheet metal specialty building contractor and HVACR Class A trade licenses$50,000
ArkansasResidentialHVACR Class B trade and HVACR registrationHVACR Class D trade and HVACR registrationNone
CaliforniaBothWarm-air heating, ventilating and air-conditioning contractorSheet metal contractor$500
ConnecticutBothLimited air conditioning, refrigeration and warm air contractor and journeyperson licensesLimited sheet metal contractor and journeyperson licenses (commercial); Limited residential/light commercial sheet metal contractor and journeyperson licenses (residential)None
District of ColumbiaBothRefrigeration and air conditioning contractor and limited master mechanic licenses(Same)None
DelawareBothMaster HVACR(Same)None
FloridaBothMechanical contractor certificationSheet metal contractor certification $2,500
GeorgiaCommercialConditioned air contractor, Class II(Same)None
GeorgiaResidentialConditioned air contractor, Class I(Same)None
HawaiiBothVentilating and air conditioning specialty contractorSheet metal specialty contractor$1,000
IdahoBothHVAC contractor, journeyman and apprentice licenses(Same)None
IowaBothHVAC/R contractor, master, journeyman and apprentice licenses as well as construction contractor registration(Same)None
KentuckyBothMaster HVAC contractor, journeyman mechanic and apprentice licenses(Same)None
LouisianaBothMechanical contractor – HVAC, duct work and refrigeration specialtySheet metal duct work specialty contractor (commercial); Home improvement contractor (residential)HVAC: $10,000
HVAC Sheet Metal:
$50,000 (commercial),
$7,500 (residential)
MarylandBothMaster HVACR contractor, journeyman and apprentice licensesMaster restricted (ventilation) HVACR contractor, journeyman and apprentice licensesNone
MassachusettsCommercialRefrigeration technician and apprentice licensesUnlimited sheet metal journeyperson and apprentice licenses (commercial); Limited sheet metal journeyperson and apprentice licenses (residential)None
MichiganBothMechanical contractor – HVAC equipment specialty(Same)None
MississippiCommercialHVAC contractor(Same)$50,000
MississippiResidentialResidential remodeler(Same)$10,000
NebraskaBothContractor registration(Same)None
NevadaBothHeating, cooling and circulating air specialty contractorUsing sheet metal specialty contractorHVAC: None
HVAC Sheet Metal: $1,000
New JerseyBothMaster HVACR contractor, journeyperson and apprentice licenses(Same)None
New MexicoBothMechanical contractor – HVAC specialty classificationMechanical contractor – HVAC specialty classification and journeyman sheet metal licenses$7,200
North CarolinaCommercialHeating – group 3, Class I(Same)None
North CarolinaResidentialHeating – group 3, Class II(Same)None
North DakotaBothGeneral contractor – Class D(Same)$4,000
OhioCommercialHVAC contractor(Same)None
OklahomaBothHVAC/R unlimited mechanical contractor and apprentice licenses(Same)None
OregonCommercialCommercial specialty contractor – level 2(Same)$1,000
OregonResidentialResidential specialty contractor(Same)$1,000
PennsylvaniaResidentialHome improvement contractor(Same)$500
Rhode IslandBothClass II pipefitter/refrigeration master, journeyperson and apprentice licensesClass I sheet metal master, journeyperson and apprentice licenses (commercial); Class II sheet metal master, journeyperson and apprentice licenses (residential)None
South CarolinaCommercialMechanical contractor – air conditioning and heating specialtiesMechanical contractor – packaged equipment specialty$5,000
South CarolinaResidentialResidential contractor – heating and air specialty(Same)$200
TennesseeBothMechanical contractor – HVAC, refrigeration and gas piping specialty(Same)$25,000
TexasCommercialClass A environmental air conditioning contractor and ACR technician licenses(Same)None
TexasResidentialClass B environmental air conditioning contractor and ACR technician licenses(Same)None
UtahBothHVAC specialty contractorCarpentry and flooring specialty contractorHVAC: None
HVAC Sheet Metal: $3,000
VirginiaBothClass C contractor – HVAC specialty and HVAC master and journeyman tradesmen licenses(Same)$1,000
WashingtonBothHVAC/R specialty contractor(Same)$500
West VirginiaCommercialHVAC contractor License, technician certification and technician-in-training certification(Same)$25,000
West VirginiaResidentialHVAC contractor License, residential technician certification and technician-in-training certification(Same)$5,000
WisconsinBothHVAC contractor credentials(Same)None

Emergency Medical Technician

Often, states set only topics that must be covered in education requirements for emergency medical technician licenses. In such cases, we obtained education length by randomly sampling state-approved private providers or by observing national standards if the state aligns its education requirements with such standards.

Makeup Artist

Three states (Idaho, Kentucky and Nevada) issue a license specific to makeup artists, while Ohio offers a “boutique services” registration that covers makeup artistry. In 33 other states, however, makeup application is interpreted as falling under the scope of other licenses administered by cosmetology boards. While some of the 33 states exempt from licensure makeup application performed in certain settings (e.g., theatrical productions, television or retail demonstrations), this report considers the broad occupation of makeup artist to be licensed in all those states. Table B3 provides the specific type of license we observe in each state.

Table B3: Makeup Artist Licensing

Type of LicenseStates
Boutique services*Ohio
Esthetician/aestheticianAlabama, Alaska, Arkansas, California, Colorado, Delaware, D.C., Georgia, Hawaii, Illinois, Indiana, Iowa, Kansas, Louisiana, Maine, Michigan, Missouri, Montana, New Hampshire, New Mexico, New York, North Carolina, North Dakota, Oregon, Pennsylvania, South Carolina, South Dakota, Tennessee, Vermont, West Virginia and Wisconsin
Makeup artistIdaho, Kentucky and Nevada
Skin care specialistNew Jersey
*Boutique services = braiding, threading, shampooing and makeup artistry.

Midwife, Direct Entry

Direct entry midwives typically work in homes and other non-hospital settings such as birthing centers. States often define the nature of the work of direct entry midwives—providing maternity care in the birthing process—but not the setting. 10  However, the North American Registry of Midwives says Certified Professional Midwives—the certification required by many states that license direct entry midwives—work “primarily in out-of-hospital settings.” 11

Some states also prohibit the work of direct entry midwives by requiring a higher-level license than we observe in this report. For example, in 2015, the Georgia Board of Nursing banned midwives who were not Certified Nurse-Midwives from practicing midwifery. 12  In such cases, we chose not to observe the higher-level nurse’s license. In our data, we treated Georgia and six other states that require a higher-level license for midwives as prohibiting direct entry midwifery and thus did not record any license requirements for those states.

Milk Sampler

Three states (Louisiana, New Mexico and North Dakota) do not define education length for milk samplers. We therefore had to approximate it based on the education length given in Indiana. Similarly, Iowa and Maryland require experience for the occupation (usually, this is on-the-job training provided by another licensed sampler) but do not specify how long it should take; we estimated one day.

Mobile Home Installer

Federal law requires states to have minimum standards for mobile home installation and to operate an installation program to train and license installers. States that do not have their own program fall under a federal program administered by the U.S. Department of Housing and Urban Development’s Manufactured Home Installation Program. 13


In line with the principles detailed in Appendix A, this report generally observes the least restrictive possible license for a given occupation in each state. In the case of optician, this approach resulted in our observing licenses permitting significantly different duties. Fourteen states have only one option for licensure: a license that allows licensees to fit or dispense both regular eyeglass lenses and contact lenses. However, eight other states (Alaska, Arkansas, California, New York, Ohio, Rhode Island, South Carolina and Virginia) offer an option that allows licensees to fit or dispense regular eyeglass lenses only (in Arkansas and Rhode Island, this is the only option for licensure). As this is the least restrictive (or only) option in those states, this is the license observed.

In addition, similar to direct entry midwives above, one state—Delaware—regulates the setting in which opticians are allowed to work differently than the other states. The practice of optometry in Delaware includes lens dispensing, and as such, appears to not allow opticians to work without having an optometrist’s license. 14  As a result, we treat Delaware as prohibiting opticianry and, to avoid recording a different type of license, do not record any license requirements for the state.

Pharmacy Technician

In two states, Oklahoma and Rhode Island, pharmacy technicians must receive experience via on-the-job training with the employing pharmacy. Though the states require that the training cover certain topics, they do not specify how long the training should be. As it happens, most of the required topics closely align with the National Healthcareer Association’s pharmacy technician certification training. Because of this similarity, we use NHA’s training program length (600 hours) for Oklahoma and Rhode Island.

Public School Teacher

Some states offer preliminary licenses for public school teachers, including two teaching occupations studied in this report: public preschool teachers, who must be licensed teachers in all 50 states that license them, and head coaches for high school sports, who must be licensed teachers in five of the 47 states that license them. These licenses are less burdensome than those states’ continuously renewable professional teaching licenses, but they are also only temporary: To continue teaching, teachers must eventually convert them to a continuously renewable license by logging teaching experience on the preliminary license and completing a mentoring or teacher induction program. In keeping with the principles outlined in Appendix A, this report therefore observes the requirements for states’ continuously renewable licenses, which include the requirements for a preliminary license where required as a prerequisite.

In the public preschool teacher occupation, 16 states require only the continuously renewable professional teaching license: Alabama, Arkansas, the District of Columbia, Florida, Illinois, Minnesota, Mississippi, Montana, Nebraska, Nevada, Ohio, Oklahoma, South Dakota, Texas, Virginia and Wyoming. The remaining 34 licensed states require a preliminary license before they will issue the continuously renewable one.

In the head coach occupation, three states (Arkansas, Oklahoma and Virginia) have only the continuously renewable professional teaching license. The other two states that require coaches to be teachers (Georgia and New Jersey) require a preliminary license before they will issue the continuously renewable one.


Three states (Alabama, Louisiana and Nevada) issue a license specific to shampooers, though their titles differ. Ohio’s “boutique services” registration and Utah’s “hair safety” permit cover shampooing among other duties. In 28 states, shampooing is interpreted as falling under the scope of other licenses administered by barbering and cosmetology boards. And, because those 28 states do not specifically exempt shampooing from licensure, this report considers them as licensing the broad occupation of shampooer. Table B4 provides the specific type of license we observe in each state.

Table B4: Shampooer Licensing

Type of LicenseStates
BarberDelaware, Kansas, Mississippi, Montana, New Jersey, New Mexico, New York, Oklahoma, Rhode Island, Vermont, Washington, Wisconsin and Wyoming
Barber assistant/technicianSouth Carolina and Texas
Boutique services*Ohio
CosmetologistIowa, Kentucky**, Massachusetts, Michigan, Nebraska, North Dakota and South Dakota
Hair safetyUtah
Hairstylist/dresser/cutter/designerArkansas, California, Colorado, Hawaii and Idaho
Natural hair careOregon
Shampoo assistant/technician/technologistAlabama, Louisiana, Nevada
*Boutique services = braiding, threading, shampooing, and makeup artistry.
**Kentucky exempted shampooers from licensure in mid-2022 after the close of our research period.

Travel Guide

Travel guides work in a variety of settings, including fishing, hunting and rafting, to name only a few. Some states license travel guides working in only a single setting. For example, a state might license hunting guides but no other types of travel guides. In cases of states that license more than one setting, we used the setting requiring the least burdensome license. This approach creates variation in the type of license observed across states. The type of travel guide license observed in each state is listed in Table B5 below.

Table B5: Travel Guide Licensing

Type of LicenseStates
FishingAlaska (freshwater), Georgia (saltwater), Idaho, Illinois, Indiana, Louisiana, Maryland (freshwater), Massachusetts (saltwater), Nevada, New Hampshire, North Dakota, Oklahoma, Pennsylvania, Rhode Island (saltwater), South Carolina (saltwater), Texas (freshwater), Virginia (saltwater) and Washington (freshwater)
HuntingArizona, Delaware, Hawaii, Kentucky, Montana, New Mexico, Utah and Wyoming (deer/antelope only)
Hunting and fishingConnecticut, North Carolina, Tennessee (and trapping) and Wisconsin (and trapping)
Hunting or fishingArkansas
Recreation (hiking, camping, etc.)Maine, New York and Oregon
River raftingColorado
General guide (any of the above)California and West Virginia