The core difference between an LLC and a PA is who’s allowed to use them. A limited liability company is a general-purpose business structure open to almost anyone, while a professional association is a corporate entity reserved for people who hold a state-issued professional license. For many licensed professionals, the LLC vs. PA question isn’t really a preference at all: some states forbid doctors, lawyers, and other licensed practitioners from using a standard LLC and require a PA, professional corporation, or professional LLC instead. Where you do have a choice, the decision turns on taxation, governance formalities, and how comfortable you are with corporate paperwork.
Who Can Form Each Entity
A standard LLC is available to virtually any type of business. Retail shops, consulting firms, real estate investors, freelancers, and tech startups all use LLCs because the structure imposes no restrictions on the owner’s profession or credentials.1U.S. Small Business Administration. Choose a Business Structure Any individual or entity can be a member, and no license is required.
A PA is narrower. It exists for people who provide services requiring a state-issued professional license, and state professional service corporation acts list the qualifying fields. The roster almost always includes physicians, attorneys, dentists, certified public accountants, architects, and engineers. Some states extend it to veterinarians, chiropractors, and insurance agents. If your profession isn’t on your state’s list, you can’t form a PA.
Several states go further and prohibit licensed professionals from using a standard LLC at all. In those jurisdictions, a doctor or lawyer who wants entity protection must form either a PA (sometimes called a professional corporation or PC) or a professional limited liability company (PLLC). The rules vary by state and sometimes by profession within the same state, so checking your state’s business organizations code before filing anything is essential.
Ownership inside a PA carries its own restriction. Shareholders must hold an active license to practice the same profession the entity provides, and the same rule generally applies to managers and officers. A law firm structured as a PA cannot bring in an unlicensed investor as a shareholder, regardless of the capital on offer. If a shareholder loses their license through discipline, non-renewal, or retirement, they must give up their ownership interest. Most state statutes require this to happen promptly, and failure to remove an unlicensed owner can trigger dissolution proceedings by the secretary of state or the licensing board.
The PLLC Option Sitting Between Them
Any licensed professional comparing an LLC to a PA will run into a third form: the professional limited liability company, or PLLC. A PLLC pairs the LLC’s flexible management and pass-through taxation with the ownership restrictions of a PA. All members must be licensed in the same profession, and personal malpractice exposure remains, but you avoid the corporate governance apparatus that comes with a PA.
The practical gap shows up at tax time. A PA defaults to C-corporation treatment, meaning the entity pays corporate income tax before anything reaches shareholders. A PLLC defaults to partnership treatment, or disregarded-entity treatment if you’re the sole member, so profits flow directly to your personal return without an entity-level tax. Both can elect S-corporation status, but the default shapes your planning from day one.
Not every state offers the PLLC form, and some states that do restrict it to certain professions. Where both a PA and a PLLC are available, the decision usually comes down to whether you want corporate-style governance or the leaner operating-agreement model of an LLC.
How Each Entity Handles Personal Liability
Both LLCs and PAs create a legal barrier between the business’s debts and the owners’ personal assets. If the entity defaults on a commercial lease or a vendor invoice, creditors generally cannot reach the owners’ personal accounts or homes unless someone signed a personal guarantee. That protection works the same way in both structures.
Malpractice is where the two separate in a way that matters. In a PA, every practitioner remains personally liable for their own professional negligence and for the negligence of anyone working under their direct supervision. If a patient sues a surgeon for a botched procedure, the surgeon’s personal assets are exposed regardless of the corporate form. The PA’s liability shield doesn’t extend to the professional conduct that licensing boards regulate.
Where the PA does help is colleague-to-colleague exposure. If your law partner commits malpractice on a case you had nothing to do with, the PA structure generally prevents that judgment from reaching your personal assets. You’re shielded from your colleagues’ mistakes, just not from your own. A standard LLC serving a non-professional business doesn’t involve this carve-out because its owners aren’t subject to professional licensing obligations in the first place.
Many states require professional entities to carry malpractice or professional liability insurance as a condition of maintaining their corporate registration. Required coverage amounts vary by state and profession. Even where insurance isn’t legally mandated, carrying adequate coverage is practically essential given the personal exposure no entity structure can eliminate.
Tax Treatment
Default Classifications
The IRS classifies LLCs and PAs differently out of the box, and those defaults shape everything that follows. A single-member LLC is treated as a disregarded entity, meaning the IRS ignores it and the owner reports all business income on their personal return. A multi-member LLC is treated as a partnership, with profits and losses flowing through to each member’s individual return.2Internal Revenue Service. Limited Liability Company – Possible Repercussions Neither arrangement creates an entity-level tax.
A PA is a corporation under state law and defaults to C-corporation status for federal tax purposes. The entity pays income tax at the 21% corporate rate on its taxable income, and shareholders pay tax again when they receive dividends.3Office of the Law Revision Counsel. 26 U.S. Code 11 – Tax Imposed That second layer of tax is the single biggest reason many professionals look for alternatives to the PA.
The S-Corporation Election
Both LLCs and PAs can elect to be treated as S corporations, which eliminates the double taxation. An S corporation passes income through to shareholders’ personal returns while still allowing owners to be treated as employees of the business.4Internal Revenue Service. S Corporations To qualify, the entity must have no more than 100 shareholders, all of whom must be U.S. citizens or residents, and only one class of stock is allowed.5Office of the Law Revision Counsel. 26 U.S. Code 1361 – S Corporation Defined
Professionals often favor the S-corp election because of how it handles payroll taxes. In a standard LLC taxed as a partnership, active members typically owe self-employment tax on their entire share of net income. In an S corporation, only the salary you pay yourself is subject to payroll taxes; remaining profits distributed as shareholder dividends are not. The catch is that the IRS requires your salary to be reasonable compensation for the work you actually perform. Setting an artificially low salary to minimize payroll tax is one of the most common audit triggers for professional S corporations.
Personal Service Corporation Rules
A PA that stays taxed as a C corporation can also be classified as a qualified personal service corporation. If substantially all of its activities involve services in fields like health, law, engineering, architecture, accounting, actuarial science, consulting, or performing arts, and at least 95% of the stock is owned by employees performing those services, the IRS treats the entity as a PSC.6Internal Revenue Service. Entities 5 – Section: Personal Service Corporation
A PSC must use a calendar year as its tax year unless it can demonstrate a legitimate business purpose for a different fiscal year to the IRS. Income deferral to shareholders doesn’t count.7Office of the Law Revision Counsel. 26 U.S. Code 441 – Period for Computation of Taxable Income For a practice that would benefit from a fiscal year-end aligned to its busy season, this restriction limits planning flexibility.
Governance and Ongoing Compliance
Because a PA is a corporation, it inherits the full corporate governance apparatus. You need a board of directors, designated officers, formal bylaws, and annual meetings with recorded minutes. State professional service corporation acts generally require these formalities and treat noncompliance as grounds for administrative action. Formation documents must usually include details about the professional services the entity will provide and certify that all shareholders are properly licensed, and many states require separate registration or approval from the relevant licensing board on top of the filing with the secretary of state.
LLCs operate under a different model. Instead of bylaws and a board, an LLC is governed by an operating agreement the members draft themselves. That document can be as detailed or as simple as the members want, covering profit allocation, voting rights, management responsibilities, and exit procedures. Members choose whether to manage the business collectively or delegate authority to one or more designated managers.8Internal Revenue Service. LLC Filing as a Corporation or Partnership Most states do not require LLCs to hold annual meetings, keep formal minutes, or maintain a corporate ledger.
Both entity types must file periodic reports with the secretary of state and pay the associated fees to stay in good standing. PAs often face additional requirements that standard LLCs don’t, including annual registration with the professional licensing board and proof that all owners remain actively licensed. Some states also impose per-member fees on professional entities. The consequences of a lapse differ too. A PA that falls out of compliance with its licensing board can lose its certificate of registration and must stop providing professional services immediately; a non-professional LLC that misses filings typically faces administrative dissolution, which is disruptive but doesn’t carry professional licensing consequences.
Choosing Between Them
Start with eligibility. If your state requires licensed professionals in your field to use a PA, PC, or PLLC, the LLC option isn’t on the table and the real choice is between the PA’s corporate structure and the PLLC’s operating-agreement model. If your state does allow licensed professionals to use a standard LLC, weigh the PA’s default double taxation and governance requirements against the LLC’s lighter structure, remembering that an S-corp election is available either way. And whichever entity you form, no structure protects you from your own professional negligence, so adequate malpractice coverage sits alongside the entity choice rather than being replaced by it.