What entity should your ABA practice use in Washington?

Is ABA a licensed profession in Washington, and under which agency

Yes. The Department of Health licenses behavior analysts and assistant behavior analysts and certifies behavior technicians under chapter 18.380 RCW, enacted in 2015 (2015 c 118). The practice restriction is unconditional: "no person may engage in the practice of applied behavior analysis unless he or she holds a license or a temporary license under this chapter" (RCW 18.380.020(1)(a)). The exemptions cover other state-credentialed professionals acting within scope, federal employees, school employees, students, trainees, family members implementing a plan, animal work, and organizational consulting that involves no direct services (RCW 18.380.030). Nothing in the chapter authorizes an entity to practice, and nothing exempts a licensee's employer. The license mechanics are on the Washington licensing and credentialing page. What the license does to the entity question is the subject of this one.

The entity menu: what an ABA practice can use

Washington offers both professional forms, and both statutes are written as permissions rather than mandates. The reason a Washington ABA practice should treat them as the only forms available is not in the entity statutes; it is in the corporate-practice doctrine those statutes were enacted to carve exceptions from.

Can a behavior analyst form the professional entity

Yes. "A person or group of persons duly licensed or otherwise legally authorized to render the same professional services within this state may form and become a member or members of a professional limited liability company" (RCW 25.15.046(1)), and a professional service corporation may be organized by "an individual or group of individuals duly licensed or otherwise legally authorized to render the same professional services" (RCW 18.100.050(1)). "Professional service" is any service that requires a license as a condition of rendering it (RCW 18.100.030), and behavior analysis has required one since 2015. A licensed behavior analyst can therefore form either entity, and the PLLC is subject to every PSC Act provision that applies to a professional corporation, with "member" read for "shareholder" and "manager" for "director" (RCW 25.15.046(2), (4)). The professional entity is where a Washington ABA practice should live, not because the entity statutes compel it, but because they are the legislature's authorization for what the doctrine otherwise forbids.

Who is allowed to own it

A PLLC or professional service corporation may be owned only by persons licensed to render the same professional service, and a member who loses the license must sever all employment with and financial interest in the entity (RCW 18.100.050(1), 18.100.100; applied to PLLCs by RCW 25.15.046(2)). Whether a non-licensee may instead own a standard LLC that employs licensed behavior analysts is the question the rest of the country answers by asking whether its corporate-practice rule reaches the profession. In Washington the Supreme Court has already answered how the rule is scoped: it applies wherever "the practice of certain professions requires a license," and an entity practices such a profession "by employing a licensed individual to engage in such conduct." It rejected, in terms, the argument that the doctrine "restricts only who may own a medical practice and does not address whom that practice may employ" (Columbia Physical Therapy, 168 Wn.2d at 431). Applied to chapter 18.380, a non-licensee-owned LLC that employs licensed behavior analysts is engaged in the practice of applied behavior analysis and is not a person who holds a license. No Washington court has said so about ABA, no Department of Health enforcement action has tested it, and many Washington practices are structured this way. That is a description of unlitigated exposure, not of permission. The conservative structure, and the one this guide recommends, is a licensee-owned PLLC with the non-licensee's capital and administration in a management company that provides services to the practice and does not employ its clinicians.

Where the two archetypes split

In most states the two-archetype question is whether adding a psychologist makes an open state strict. In Washington the ABA-only practice is already inside the doctrine, so the question becomes whether the two professions can share one entity, and the answer is no. The PSC Act lets health care professionals licensed under a listed set of chapters "own stock in and render their individual professional services through one professional service corporation" as though they rendered the same service; the list includes psychology (chapter 18.83) and does not include behavior analysis (chapter 18.380) (RCW 18.100.050(5)(a)). The Supreme Court read those lists as broadening what a single professional entity may do, so a profession left off them is held to the same-service rule (Columbia Physical Therapy, 168 Wn.2d at 437 to 438). A practice that adds an in-house psychologist for diagnostic evaluations therefore needs two professional entities, an ABA PLLC owned by behavior analysts and a psychology PLLC or PS owned by the psychologist, with a management company serving both. A psychologist may not be a member of the ABA PLLC and a behavior analyst may not be a member of the psychology entity. The one theory that would let a single entity carry both, that behavior analysis is a subset of psychology the way Columbia treated physical therapy as a subset of medicine, has no support in chapter 18.380, which defines the practice of applied behavior analysis on its own terms, and should not be built on.

Why the corporate-practice doctrine reaches ABA in Washington

Washington has no corporate-practice statute. The doctrine is common law, and its scope is whatever the Supreme Court has said it is. In Standard Optical, a corporation employed a licensed optometrist, exercised no control over his professional judgment, and was still held to be practicing optometry unlawfully (17 Wn.2d 323 (1943)). In Morelli, a physician and a non-physician who ran a clinic as partners had formed an illegal partnership, and the court restated "the common law rule that a corporation cannot engage in the practice of a learned profession through licensed employees unless legislatively authorized" (110 Wn.2d 555, 561 (1988)). In Columbia Physical Therapy the court was asked to confine the rule to ownership of medical practices and declined, adhering "to the traditional understanding that the corporate practice of medicine doctrine forbids employment of health care professionals by business entities or nonprofessionals absent legislative authorization," and it found the authorization for the physician-owned PLLC's employment of physical therapists in the PSC Act itself (168 Wn.2d at 431, 435 to 436). The Attorney General applies that formulation as the starting point of its own opinions on professional ownership. The legislature has considered codifying it; Senate Bill 5387 and House Bill 1675 in the 2025 to 2026 session would prohibit unlicensed entities from owning practices or employing licensed providers, and the Senate bill report restates the doctrine in the Supreme Court's words. Three things follow for ABA. The trigger is a license requirement, and chapter 18.380 supplies one. The authorization must be legislative, and chapter 18.380 supplies none. And the safe harbor is the professional entity, which is the only structure the legislature has authorized for the purpose.

Naming the entity

A Washington PLLC name must contain "professional limited liability company," "professional limited liability co.," "P.L.L.C.," or "PLLC," and must be distinguishable on the Secretary of State's records (RCW 23.95.305, applied by RCW 25.15.046(5)). A professional service corporation's name follows the PSC Act's own rule and the general corporate designator requirements. Clear the name with the Secretary of State before filing; the Secretary of State's form will default to "PLLC" if the designator is omitted.

Why choosing the entity is only half the question

Picking the form is one decision. Who may own it, and how outside capital comes in, is the other, and in Washington the first decision answers the second: the form is a licensee-owned PLLC or PS, and outside capital lives in a management company. The work is in the management services agreement. The management company may provide space, systems, billing, non-clinical staff, and administration at a fixed fair-market-value fee; it may not employ the behavior analysts, because employment of the licensees is the act the doctrine forbids, and it may not hold the equity or the votes of the PLLC. Washington's anti-rebate statute adds a second constraint on any fee that moves with referrals or clinical revenue (chapter 19.68 RCW). Decide the entity and the ownership together, and draft the management agreement against the doctrine rather than around it.

Read next: Do you need an MSO for your ABA practice in Washington?

Tax treatment as a separate layer

Entity form and tax classification are separate choices. A Washington PLLC is taxed by default as a sole proprietorship or partnership depending on the number of members and can elect corporate or S-corporation treatment; a professional service corporation is a corporation unless it makes an S election. Washington has no personal or corporate income tax and instead levies the business and occupation tax on gross receipts, which applies to the PLLC and the management company separately and makes the management fee a taxable receipt in the management company's hands. Decide the tax layer with a Washington tax adviser, and model the B&O tax on the two-entity structure before setting the fee.

Multistate practice and foreign qualification

If you operate beyond Washington, the Washington PLLC is only your home-state piece. To deliver services in another state you generally register there as a foreign entity and meet that state's own ownership and entity rules. A licensee-owned Washington PLLC will satisfy most other states. The reverse is the trap: an out-of-state group that holds its clinical entities as non-licensee-owned LLCs in permissive states cannot qualify one of them in Washington and start employing licensed behavior analysts without walking into the doctrine. Multistate groups usually standardize on a structure that satisfies the strictest state in the footprint, and for a group with Washington in it, Washington may be that state. See the practice expansion and sale page for the multistate view.

How this connects to the rest of your compliance stack

Entity choice is one layer. Others interact with it:

• Ownership and outside capital. The PLLC is licensee-owned, so outside capital needs a management company that does not employ the clinicians. See the Washington MSO and ownership page.
• Licensing and credentialing. Every member and every clinician holds the chapter 18.380 license or certification, and the entity's authorization to practice runs through its members' licenses. See licensing and credentialing in Washington.
• Payor and Medicaid enrollment. The PLLC and its ownership are disclosed at enrollment and revalidation; Apple Health's ABA benefit enrolls the agency and its licensed staff. See Washington Medicaid and the insurance mandate.

Forming the entity in Washington: the sequence

1. License the members. Every proposed member holds a licensed behavior analyst or licensed assistant behavior analyst credential from the Department of Health before filing.
2. Form the PLLC. Certificate of formation for a professional limited liability company with the Secretary of State under RCW 25.15.046; no Department of Health certificate is required at formation.
3. Clear the name. PLLC designator under RCW 23.95.305; check availability with the Secretary of State.
4. Adopt an LLC agreement. Members are licensed behavior analysts only; managers and officers other than secretary and treasurer are licensees (18.100.060 as applied by 25.15.046); a license lapse triggers mandatory severance (18.100.100).
5. If diagnostics are in-house, form the second professional entity. A separate psychology PLLC or PS owned by the psychologist; no shared entity, since 18.380 is not on the 18.100.050(5)(a) list.
6. If outside capital is involved, build the management company. Administrative services only, fixed fair-market-value fee, no employment of clinicians, no equity or voting rights in the PLLC; test the fee against chapter 19.68. Confirm with Washington counsel.
7. Watch the legislature. SB 5387 and HB 1675 would codify the doctrine; enactment would remove the "untested" qualifier from this page.

Washington entity variables at a glance

Frequently asked questions