Incorporator The Journal of U.S. Formation
Start Free Quiz
Editorial 7 MIN READ

The Series LLC, a decade and a half in

Twenty-plus states, one still-proposed federal tax rule, and a Ninth Circuit opinion that exposed the whole theory

The Editors
Staff, Incorporator.org
7 min read Updated
Contents 7 sections
  1. What Delaware actually created
  2. How the federal government sees it (and does not)
  3. The case everyone should read
  4. The Corporate Transparency Act complication
  5. Where the form actually earns its keep
  6. The practical posture in late 2024
  7. Sources

he Series LLC is a single Delaware invention from 1996 that now exists, in some form, in more than twenty states, and it still does not have a final federal tax rule. Founders keep picking it anyway, because for a small set of use cases it is the only vehicle that does what they want.

This is a status check on the form in late 2024. Where it works, where it does not travel, how the IRS and FinCEN currently treat it, and the one appellate opinion every lawyer recommending the structure should have read.

What Delaware actually created

Delaware added the series provision to its LLC Act as 6 Del. C. § 18-215 in 1996. The statute lets a single LLC establish one or more "series" of members, managers, interests, or assets, and provides that debts and obligations of one series are enforceable only against the assets of that series, not against the assets of any other series or of the LLC generally. The internal liability wall is conditional: the LLC agreement must provide for it, separate records must be maintained, and the certificate of formation must give notice of the limitation.

The drafting history is worth knowing. The provision was adopted so that mutual funds organized as Delaware statutory trusts could instead use an LLC structure, with each portfolio inside one legal entity insulated from claims against the others. It was a capital-markets fix, not a retail real-estate product. The retail re-purposing came later.

By the late 2010s the form had traveled. As of 2024, Series LLCs are authorized in Delaware, Illinois, Iowa, Kansas, Missouri, Montana, Nevada, Oklahoma, Tennessee, Texas, Utah, the District of Columbia, North Dakota, Nebraska, Alabama, Wisconsin, Virginia, Indiana, Arkansas, South Dakota, and Wyoming, with the adopting states drawing variously on Delaware's statute and on the Uniform Protected Series Act approved by the Uniform Law Commission in 2017. Four of the largest commercial-litigation states, California, New York, Massachusetts, and Florida, have not adopted the form, though Florida did enact its own "protected series" concept as part of its 2015 revised LLC act at Fla. Stat. ch. 605.

How the federal government sees it (and does not)

Fourteen years ago, in September 2010, Treasury and the IRS published proposed regulations under Prop. Reg. § 301.7701-1(a)(5) treating each series of a domestic series LLC as a separate entity for federal tax purposes, classifiable under the check-the-box rules the same way a standalone LLC is classified. The rule would mean each series files its own return, obtains its own EIN, and is treated as its own disregarded entity, partnership, or corporation as elected.

That rule is still proposed. In October 2024, fourteen years after publication, there is no final regulation. Practitioners have been relying on the proposed regulation's framework, because there is nothing else to rely on, and the IRS has neither withdrawn the proposal nor finalized it. EIN issuance practice at the Service has in fact followed the proposed approach: each series can obtain its own EIN and be treated as a separate taxpayer. But the formal legal posture is that the question remains open, and any audit that wanted to litigate series-level classification would be litigating into a vacuum.

State tax treatment is even messier. Some states track federal classification. Others, notably Illinois and Texas, have their own series-level franchise-tax and filing regimes that require attention independent of the federal position. A Texas series LLC pays franchise tax on a combined basis, but each series may be counted separately for registered-agent and public-information purposes.

The case everyone should read

The best-known appellate test of the series liability shield went badly for the theory. In Sen. Graham v. Series I, 647 F.3d 1138 (9th Cir. 2011), the Ninth Circuit considered whether a judgment creditor of one series of a Texas series LLC could reach assets of other series, and whether California, where the litigation was pending, was required to give full faith and credit to the Texas internal-liability structure.

The court held that California was not required to recognize the Texas series partition in the way the debtor argued. A state that has not itself adopted the series-LLC form is not obligated to treat the internal walls as substantive limits on creditor remedies in the way the organizing state does. The holding is narrow on its facts, and lawyers disagree about how far it travels, but it is the single clearest signal that the liability shield inside a series LLC is only as strong as the forum state's willingness to honor it.

For a Delaware series LLC doing business in California, that is an uncomfortable place to be. Operations-state creditors will often sue in the operations-state courts, and those are the courts that must decide whether to enforce the partition. A conservative reading of Graham is that in any non-adopting state, the internal liability walls may fail at precisely the moment they are needed.

The Corporate Transparency Act complication

The Corporate Transparency Act, 31 U.S.C. § 5336, took effect on January 1, 2024, requiring most domestic reporting companies to file beneficial-ownership information with FinCEN. The statute was drafted before the series-LLC question received close attention, and the form asks what counts as a "reporting company" when one legal entity contains many nominally separate cells.

FinCEN addressed this in guidance updated through January 2024. The agency's position, reflected in the FAQ and in the Small Entity Compliance Guide, is that in states where each series is itself a separate legal entity created by a filing with the secretary of state, each such series is its own reporting company with its own BOI obligation. In states where a series is not separately formed by a public filing but is only an internal partition of the umbrella LLC, the umbrella is the reporting company and the internal series is not. Practically, that means Illinois- and Texas-style "registered" or filed series are each going to have their own BOI report, while Delaware-style internal-only series are typically not.

The result for a real-estate sponsor who organized a single Delaware series LLC with forty internal property series in 2022 is a single BOI filing. The same sponsor who did the same thing in Illinois, filing a certificate for each series, may owe forty.

Where the form actually earns its keep

Three use cases have held up, and one has not.

Captive insurance is the cleanest case. A parent forms a series LLC to hold segregated cells for different insured risks, and the cell structure is recognized by state insurance regulators. The form was designed for this kind of compartmented, regulated, single-sponsor vehicle.

Multi-property residential real estate is the most marketed case, and the most contested. The pitch is that a sponsor with thirty single-family rentals can put each into its own series and avoid thirty separate LLC filings, thirty annual fees, and thirty registered agents. The dollars save. The risk is Graham-shaped: if any of those properties is outside the organizing state, the liability wall is exposed to forum-state skepticism in exactly the suits the structure was meant to blunt. For a sponsor with all properties inside Delaware, Illinois, or Texas, and with counsel and insurance matched to that posture, the math works. For a sponsor with properties across eight states, a conventional holding structure of separate single-property LLCs is often still the right answer despite costing more.

Fund-of-funds and parallel-fund structures used the form the way Delaware originally intended. Each portfolio is its own series, the internal walls are honored by sophisticated counterparties and their counsel, and the whole arrangement sits inside a regulatory and contractual environment where the Delaware statute is the governing frame. This is the least controversial deployment and the one most aligned with the original legislative intent.

The use case that has not held up is the one-person operational business trying to subdivide a single trade into series for liability partitioning. The administrative discipline required (separate books, separate bank accounts, separate contracts executed in the name of the specific series) tends not to survive contact with a sole proprietor's operational reality, and a poorly maintained series is exactly the fact pattern that invites a court to collapse the partition.

The practical posture in late 2024

The Series LLC in October 2024 is a mature, widely adopted form with a still-incomplete federal tax framework, a single unfavorable appellate opinion in a non-adopting state, and a new federal reporting regime that treats it inconsistently depending on how the state structures its series registration.

For the narrow set of uses the form was built for, captive insurance, segregated funds, and in-state real-estate portfolios run with professional discipline, it is the right tool. Outside that band, the savings in filing fees are small relative to the cost of finding out, in litigation, that the internal wall does not hold. A sponsor who has been sold a series LLC as a cheap substitute for separate entity formation in multiple states is being sold the 2010 marketing pitch, not the 2024 legal reality.

The still-proposed status of Prop. Reg. § 301.7701-1(a)(5) is, after fourteen years, its own quiet data point about how confident Treasury is in the underlying theory. Final rules usually happen when the agency is ready to defend them. This one has not.

Sources

Keep reading

More from the journal.