To become a licensed private investigator in Maine, you must be at least 21, pass a background check, meet one of four education or experience pathways, submit an application to the Maine State Police Special Investigations Unit, pass a written exam, and obtain commercial general liability insurance. The process typically takes several months from application to license issuance.
In Maine, private investigators are officially called professional investigators, and they’re licensed and regulated by the Maine State Police Special Investigations Unit. The licensing process is more involved than in many states — it requires documented experience or education, a written examination, a background check, and commercial liability insurance before you can practice. Here’s exactly what that looks like, step by step.
Maine calls its licensed PIs “professional investigators” — a distinction that matters when you’re filling out applications, searching for licensing forms, or explaining your credentials to clients. The license is issued by the Maine State Police, not a separate licensing board, which shapes everything from how applications are processed to where you mail your paperwork.
Step 1. Meet General Qualifications for Professional Investigators in Maine
Before you start gathering documents or logging hours, make sure you meet these baseline requirements. They’re non-negotiable — failing any one of them disqualifies your application regardless of your experience:
- You must be at least 21 years old
- You must be a U.S. citizen or lawful permanent resident
- You must be a high school graduate or hold a GED
- You must have good moral character, which the Maine State Police evaluates based on your criminal and civil record. Disqualifying factors include:
- Any conviction for a crime punishable by more than one year of imprisonment
- Domestic abuse incidents involving family or household members in the past five years
- Three or more Class D or E criminal convictions in the past five years
- Three or more civil violations in the past five years
- Negligent or reckless conduct endangering others in the past five years (including incidents involving vehicles or weapons)
- Failure to meet child or family support obligations
- A dishonorable discharge from military service
- You must meet one of the education or experience pathways described in Step 2
- You must pass the Maine Professional Investigators Examination (Step 4)
Step 2. Complete Education and Experience Requirements for Professional Investigators in Maine
Maine offers four pathways to qualify for the licensing examination. Most applicants will fall into Option 1 (the Investigative Assistant sponsorship route) or Option 3 (law enforcement experience). Read each one carefully — there’s more flexibility here than many states offer, and the right combination of education and experience could open a shorter path than you’d expect.
- Option 1: Complete 60 college credits in private investigation or a related field, or earn a certificate of study in private investigation, and complete at least 1,200 hours in an investigative assistant sponsorship program supervised by a licensed professional investigator.
- Option 2: Have at least three years of full-time experience as a federal detective or investigator with the U.S. Armed Forces or a federal investigative agency.
- Option 3: Have at least three years of employment as a law enforcement officer of a state or jurisdiction, meeting that jurisdiction’s training requirements.
- Option 4: Have at least six years of combined experience, which must include:
- At least two years of non-clerical work experience in a profession related to criminal justice or law, and
- One of the following education credentials: an associate degree from an accredited institution in criminal justice, law, investigation, security management, police administration, or computer forensics, or 60 college credits in one of those disciplines.
The Investigative Assistant Pathway
If you’re new to the field and don’t have law enforcement or federal investigative experience, Option 1’s investigative assistant sponsorship program is the structured entry path Maine has built for you. You’ll work under a licensed professional investigator and log your hours in a state-issued training log. The Maine State Police requires a proof-of-hours letter from your sponsoring PI when you apply, so keep meticulous records from day one.
Maine also licenses investigative assistants separately. If you want to start building your hours legitimately before you meet the full requirements to apply for a professional investigator license, applying for an investigative assistant license first is the practical move. The Maine State Police Special Investigations Unit handles both applications.
Reciprocity
If you’ve held a private investigator license in another state or territory for at least three years, you may qualify for an exemption from Maine’s education and experience requirements — and possibly from the state examination as well. Two conditions must be met: that the state must grant reciprocity to Maine-licensed investigators, and its licensing requirements must be substantially equivalent to Maine’s. Contact the Special Investigations Unit directly to confirm whether your home state qualifies before applying.
Firearms Certification
If you intend to carry a firearm while working, you must meet Maine’s handgun permit and training requirements. Maine allows permitless concealed carry for eligible individuals, though certain employers or client situations may still require formal permitting or documented training. Carrying a firearm is not a requirement for all licensees.
Step 3. Submit Your Maine Professional Investigator License Application
Once you’ve confirmed you meet the qualifications and have documented your experience pathway, you’re ready to submit the Maine Application for Professional Investigator License. Submit it with all supporting documentation to the Department of Public Safety, Maine State Police, Special Investigations Unit, 45 Commerce Drive, Augusta, ME (mailing address: State House Station 164, Augusta, ME 04333).
Along with the completed application, you must include:
- Check or money order payable to Treasurer, State of Maine, for $71 (application fee of $50 plus State Bureau of Identification record check fee of $21). A final license fee is also due when you pass the Maine Professional Investigators Exam, prior to license issuance. Fees are subject to change. Confirm current amounts with the Maine State Police Special Investigations Unit before submitting.
- Copy of your high school diploma or GED
- Copy of your birth certificate or permanent resident card
- Copy of your military discharge, if applicable
- Copies of any law enforcement academy training certificates and transcripts, if applicable
- Copy of your college diploma and transcripts, if applicable
- Documentation of your work history (jobs, duties, and dates) signed by each employer
- Three character references from people who have known you for at least three years (included in the application form). They must reside in the community where you live, work, or plan to work.
- Signed Form P-3, authorizing law enforcement agencies, courts, military forces, government agencies, hospitals, and medical and mental health facilities to release information to the Maine State Police Special Investigations Unit for evaluation of your application
- Signed Authorization to Release form for the Dorothea Dix Psychiatric Center and the Riverview Psychiatric Center (required with all applications, even if you were never a patient at either facility)
- Signed Form 577, Client Authorization for the same psychiatric centers (also required with all applications)
Step 4. Pass the Maine Professional Investigators Examination
After the Maine State Police receives your application and completes the background check, they’ll contact you to schedule the Maine Professional Investigators Examination. The exam is typically offered monthly (often on the third Thursday). It consists of 50 multiple-choice and true-false questions, and you need to score at least 76 percent to pass.
The exam covers three main areas:
- Laws relating to professional investigators
- Laws relating to permits to carry concealed handguns
- Title 17-A, Maine Criminal Statutes, Parts 1 (General Principles) and 2 (Substantive Offenses)
Once you pass, the Maine State Police will send an approval letter to your insurance company, which triggers the next step.
Step 5. Obtain Commercial General Liability Insurance
Before your license can be issued, you must obtain an occurrence-based Commercial General Liability insurance policy from an insurer licensed to do business in Maine by the Maine Bureau of Insurance. The minimum required coverage amounts are:
- Property damage: $10,000
- Each occurrence limit: $100,000
- General aggregate limit: $200,000
Your name must appear on the policy. If your employer also carries liability insurance, your employer’s name must appear alongside yours. Proof of insurance must identify the Certificate Holder as: Maine State Police, Special Investigations Unit, 164 State House Station, Augusta, ME 04333.
You must also submit a Surety Bond to the Maine State Police Special Investigations Unit — $10,000 if you’re a Maine resident, $50,000 if you’re not. The bond must be executed by a surety company authorized to operate in Maine.
Once your insurance company issues the bond and proof of commercial general liability coverage, and you submit the final license fee to the Maine State Police, your professional investigator’s license will be issued.
Step 6. Maintaining and Renewing Your Maine Professional Investigator License
Your initial professional investigator license is valid for two years. After that first renewal, you renew every four years. Renewal requires submitting the same three Authorities to Release forms you submitted with your original application, along with:
| Renewal Item | Details |
|---|---|
| Completed renewal form | Professional Investigator License Renewal form |
| Renewal fee | $521 via check or money order payable to Treasurer, State of Maine (application fee of $500 plus $21 State Bureau of Identification record check fee). Fees are subject to change. Confirm current amounts with the Maine State Police. |
| Three Authorities to Release forms | Same forms submitted with original application (Form P-3, Authorization to Release, Form 577) |
The Special Investigations Unit takes approximately 6 to 8 weeks to process renewal applications. After approval, you’ll receive a letter requesting a four-year continuation certification from your insurance company. Submit that certification, along with proof of current commercial general liability insurance and a recent photograph of yourself, to the Maine State Police Special Investigations Unit. If you’ve changed insurance companies, include a new surety bond form as well.
Private Investigator Salary in Maine
BLS data shows Maine private investigators earned a median annual salary of $49,360 as of May 2024, with the top 25% earning $54,930 or more. The state employs approximately 200 professional investigators. The BLS projects 3.1% employment growth for private investigators in Maine between 2022 and 2032, with an average of 30 job openings per year. Due to Maine’s relatively small PI workforce, BLS figures may reflect broader regional estimates rather than precise state-specific data.
Salaries by Metro Area in Maine
| Metro Area | Median Annual Salary | 90th Percentile |
|---|---|---|
| Portland-South Portland, ME | $53,770 | $72,710 |
| Lewiston-Auburn, ME | $41,250 | $53,720 |
| Southwest Maine nonmetropolitan area | $49,360 | $72,180 |
Portland-South Portland is Maine’s strongest market for PI compensation, with median earnings well above the state figure and top earners approaching the national 90th percentile. Lewiston-Auburn has a smaller PI workforce and correspondingly lower wages, but remains a viable market for investigators working the central Maine corridor.
Frequently Asked Questions
What is the difference between a professional investigator and an investigative assistant in Maine?
A professional investigator holds a full license issued by the Maine State Police and can operate independently. An investigative assistant works under the direct supervision of a licensed professional investigator and cannot take cases independently. The investigative assistant pathway is how most new entrants build the 1,200 hours of documented experience required to qualify for the full professional investigator license under Option 1.
How long does it take to get a PI license in Maine?
Most applicants should plan for 2 to 4 months from the time they submit a complete application to the time they receive their license, depending on processing times and the completion of background checks. The exam is offered monthly, so timing your application to clear the background check before the next exam date is worth considering. If you’re pursuing Option 1, add the time needed to complete 1,200 supervised hours before you’re eligible to apply.
Does Maine have reciprocity with other states for PI licensing?
Maine does offer reciprocity, but it’s conditional. Your home state must grant reciprocity to Maine-licensed investigators, and its requirements must be substantially equivalent to Maine’s. If both conditions are met, you may be exempt from the education and experience requirements and possibly from the licensing exam as well. Contact the Maine State Police Special Investigations Unit at (207) 624-7210 to verify whether your state qualifies before submitting an application.
What does the Maine PI licensing exam cover?
The exam consists of 50 multiple-choice and true-false questions covering three areas: laws governing professional investigators, laws relating to concealed carry permits, and Title 17-A of Maine Criminal Statutes (Parts 1 and 2, covering general principles and substantive offenses). You need to score 76 percent or higher to pass. The exam is typically offered monthly. Contact the Special Investigations Unit for the current schedule.
Do I need a college degree to become a PI in Maine?
No, but education can help you qualify faster through some pathways. Under Option 4, an associate degree or 60 college credits in criminal justice, law, or a related field is required, along with 2 years of relevant work experience. Under Option 1, 60 credits (or a certificate) in private investigation or a related field must be combined with 1,200 supervised hours. If you have a solid background in law enforcement or federal investigation, Options 2 and 3 require no college credits at all.
Key Takeaways
- Maine calls them “professional investigators”: licensing is handled by the Maine State Police Special Investigations Unit, not a separate board.
- Four qualification pathways exist: law enforcement experience, federal investigative experience, the investigative assistant sponsorship route, or a combination of education and criminal justice work history.
- The investigative assistant license is a separate, supervised entry-level credential that lets you start building the hours needed for a full professional investigator license.
- A written exam is required: 50 questions, 76% passing score, offered monthly.
- Insurance and bond must be in place before the license is issued: commercial general liability coverage and a surety bond ($10,000 for residents, $50,000 for non-residents).
- Median salary of $49,360 per BLS May 2024 data, with Portland-South Portland PIs earning a median of $53,770.
Ready to start building your qualifications? Browse criminal justice and PI-related programs in Maine to find the education that fits your licensing pathway.
May 2024 US Bureau of Labor Statistics salary and job market figures for Private Detectives and Investigators reflect state and national data, not school-specific information. Conditions in your area may vary. Data accessed May 2026.