The locum arrangement: agencies, agreements, and billing under Q6

How to hire a locum: the sequence

Hire a locum in a fixed order so nothing that protects your license or your billing gets skipped under time pressure. Source a qualified substitute, agree on terms in writing, verify their license and credentials, screen them against the federal exclusion list, decide the billing path before they see a patient, and give them scoped, logged access to your systems. Only then does the coverage begin.

• Source through a locum agency or your own professional network.
• Agree in writing on dates, scope, day rate, malpractice coverage, and any restrictive covenant.
• Verify and credential the license, and re-credential with payers where required.
• Screen against the OIG exclusion list before the first shift.
• Set the billing path — the locum's own enrollment, supervised billing, or a substitute-billing modifier.
• Provision access to the EHR with the minimum necessary, and log it.

Finding a locum: an agency or your own network

You have two sourcing routes, and neither is wrong. A locum agency does the searching, verifies credentials, and often carries malpractice coverage, in exchange for a markup on the day rate. Sourcing directly — through the solo web of colleagues you already trade referrals with — costs less and gives you someone you may already trust, but the verification, contracting, and coverage checks fall to you. For a short, planned absence, either can work.

A standing arrangement often beats a scramble. Many solo clinicians set up a coverage pact in advance — a colleague who agrees to cover your panel when you are out, and whom you cover in return — so the substitute is known and pre-credentialed before the emergency, not sourced during it. If the locum is really a first step toward adding permanent help, treat it as the first hire and structure the agreement so it can convert cleanly.

The coverage agreement: what it must cover

Put the arrangement in a written agreement before the locum starts, because the terms you skip are the ones that surface as disputes. Cover the dates and scope of coverage, the day rate or percentage and how it is paid, which malpractice policy applies and whether it includes tail coverage, who owns the records of patients the locum sees, and what happens if a patient wants to keep seeing the substitute. Ambiguity here is expensive later.

Restrictive covenants deserve their own line. The FTC's 2024 rule banning most non-competes was set aside by a federal court, so employer non-competes remain governed by state law while appeals proceed — a moving target as of July 2026 1Ref 1Federal Trade Commission (2024).Noncompete Rule.That the FTC's 2024 non-compete rule was set aside by a federal court, leaving employer non-competes governed by state law while appeals proceed, as of July 2026.. Whether a non-compete or non-solicit clause in your locum agreement is enforceable turns on your state's law, not the federal rule, so write it to your state and expect a court may narrow it. A non-solicitation of patients is generally treated differently from a non-compete; both are worth counsel's eye before you rely on them.

Credentialing, enrollment, and exclusion screening

Before the locum bills a dollar, confirm they are eligible to be paid and legally clear to work. Two checks are non-negotiable: their active, unrestricted license in your state, and that they are not excluded from federal health programs. No federal program payment may be made for items or services furnished by an excluded person, and the OIG's LEIE is the free public list you screen against — do it before the first shift and keep the dated result 2Ref 2HHS Office of Inspector General (2026).Exclusions Program.That no federal program payment may be made for services furnished by an excluded person, and that the LEIE is the public list used to screen a new hire..

Payer eligibility is the next gate. Medicare covers behavioral health services only from eligible provider types; the program added marriage and family therapists and mental health counselors in 2024, and the MLN booklet lists which provider types, codes, telehealth rules, and incident-to constraints apply 3Ref 3Centers for Medicare & Medicaid Services (2025).Medicare and Mental Health Coverage.That Medicare covers behavioral health from eligible provider types, added MFTs and mental health counselors in 2024, and lists covered codes and incident-to constraints.. If your locum's discipline is not separately enrollable, the only compliant path may be supervised billing or a substitute-billing arrangement — decide that before, not after, they start seeing your patients.

Who bills, and how: incident-to versus Q6

The billing path is the decision that most often goes wrong, so settle it in advance. There are three broad options and they are not interchangeable: the locum enrolls with your payers and bills under their own number; you bill incident-to under your supervision; or you use Medicare's substitute-billing arrangement to bill the locum's services under your own number with a modifier. Each carries different conditions, and using the wrong one is a refund waiting to happen.

Incident-to has hard conditions. The regulation requires direct supervision, an employment or contract relationship, and that you personally initiated the patient's course of care and stay actively involved — miss any element and the incident-to claim is not payable 4Ref 4Office of the Federal Register (2026).42 CFR 410.26 — Services and supplies incident to a physician's professional services.The incident-to conditions — direct supervision, employment or contract relationship, and the initiating-service requirement — that must all be met for the claim to be payable.. If instead you want the substitute's services billed under your own number without them enrolling, that is Medicare's modifier Q6 territory — a distinct set of rules, with its own day limits and documentation, covered on its own page and not to be confused with incident-to. Match the path to who the patient is, who supervises, and whether the locum is enrolled.

What does a locum cost?

A locum is priced as a day rate or an hourly rate, sometimes as a percentage of collections, and an agency adds a markup on top. Benchmark the number against real wage data rather than guessing. The Bureau of Labor Statistics publishes wage distributions — median and percentiles, by state and metro — for each behavioral health discipline, which is the honest floor for what a qualified substitute in your market expects to earn.

Match the series to the discipline you are hiring: BLS wage distributions for clinical and counseling psychologists 5Ref 5U.S. Bureau of Labor Statistics (2025).Occupational Employment and Wages: Clinical and Counseling Psychologists.Official wage distributions for clinical and counseling psychologists to benchmark a psychologist locum's day rate by state and metro., for substance-use, behavioral-disorder, and mental health counselors 6Ref 6U.S. Bureau of Labor Statistics (2025).Occupational Employment and Wages: Substance Abuse, Behavioral Disorder, and Mental Health Counselors.Official wage distributions for mental health and substance-use counselors to benchmark a counselor locum's day rate by state and metro., and for healthcare social workers 7Ref 7U.S. Bureau of Labor Statistics (2025).Occupational Employment and Wages: Healthcare Social Workers.Official wage distributions for healthcare social workers to benchmark a social-worker locum's day rate by state and metro. each give the local distribution you can anchor a day rate to. Remember the total cost is more than the rate — agency markup, your malpractice endorsement, credentialing time, and the revenue the locum does or does not generate all belong in the math you run before you commit.