OSB April 2026

When the only lawyer who worked on a client's matter leaves a firm and the client follows the lawyer, can the former firm later represent parties adverse to that client without consent?

Short answer: Yes, qualified. Under RPC 1.10(b), once the lawyer who handled the client leaves and takes the client, the former firm needs the client's consent only if the new matter is the same or substantially related and a lawyer remaining at the firm holds protected information material to it. If the firm ensures no remaining lawyer has such information, by segregating, destroying, or returning the files, it may proceed without consent.

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This page answers the general question as of 2026. Ezel answers yours: whether it's allowed on your facts, under the current Oregon Rules of Professional Conduct, with citations.

Disclaimer: Advisory only. Not binding precedent.
About this page: The plain-English summary, reader guidance, and Q&A below were written by Ezel based on the official ethics opinion. The original opinion (linked on this page as a PDF) is the authoritative source for any reliance.
View original ethics opinion (PDF)

Plain-English summary

While at a former firm, a lawyer was the only lawyer who worked on or acquired information relating to a client's representation. The lawyer then left to start a new firm, and the client directed all pending and future work to the new firm. The opinion asks whether the former firm may represent parties adverse to the client without the client's consent, and answers yes, qualified.

The opinion applies Oregon RPC 1.10(b), which provides that after a lawyer leaves a firm, the firm is not barred from representing a person with interests materially adverse to a client the departed lawyer had represented, unless the matter is the same or substantially related to that representation and a lawyer remaining in the firm has information protected by Oregon RPC 1.6 and 1.9(c) that is material to the matter. Because the departing lawyer was the only one who worked on or learned about the client's matter, the former firm needs a conflict waiver only if both conditions are met.

The opinion identifies the remaining question as whether any lawyer still at the former firm acquired or is deemed to "have" protected information about the client, including through retained files or electronic documents that are material to the matter. It concludes that if the former firm takes sufficient steps to ensure no lawyer there has or will acquire that information, for example by segregating, restricting access to, or destroying the materials or returning them to the client without keeping copies, the firm will have met its obligations under Oregon RPC 1.10(b) and may proceed without consent.

In practice

The opinion holds that, under the current Oregon rules, the departure of the sole lawyer who handled a client breaks the firm's automatic disqualification: RPC 1.10(b) turns the question into whether anyone left behind actually holds material protected information. Per the opinion, a firm can put itself clearly in the clear by demonstrably eliminating access to the client's information through segregation, destruction, or return of the files. Verify the current text of Oregon RPC 1.6, 1.9, and 1.10 before relying on any specific point.

Common questions

Q: If a lawyer takes a client to a new firm, can the old firm now take cases against that client?

A: Yes, qualified. The opinion concludes that under Oregon RPC 1.10(b) the former firm may do so unless the matter is the same or substantially related and a remaining lawyer holds protected information material to it.

Q: What makes the former firm need the client's consent?

A: Per the opinion, both conditions of RPC 1.10(b) must be met: the matter is the same or substantially related to the departed lawyer's work, and a lawyer still at the firm has information protected by RPC 1.6 and 1.9(c) that is material to the matter.

Q: How can the former firm avoid the conflict entirely?

A: The opinion concludes the firm can ensure no remaining lawyer has the client's protected information, for example by segregating, restricting access to, or destroying the files, or returning them to the client without retaining copies.

Background and rules framework

The opinion interprets Oregon RPC 1.10(b) (a firm's freedom to act adverse to a departed lawyer's former client) together with Oregon RPC 1.6 (confidentiality) and 1.9(c) (use and disclosure of a former client's information), corresponding to Model Rules 1.10, 1.6, and 1.9.

Citations and references

Rules of Professional Conduct:

  • Oregon RPC 1.10(b) / Model Rule 1.10 (imputation after a lawyer leaves a firm)
  • Oregon RPC 1.6 / Model Rule 1.6 (confidentiality)
  • Oregon RPC 1.9(c) / Model Rule 1.9 (former-client information)

Cases:

  • Gas-A-Tron of Arizona v. Union Oil Co. of California, 534 F2d 1322 (9th Cir 1976)

Other opinions cited:

  • OSB Formal Ethics Op. No. 2005-120 (rev 2026) (lawyer changing firms, screening)
  • OSB Formal Ethics Op. No. 2005-17 (former client, use of confidential information)
  • OSB Formal Ethics Op. No. 2005-11 (former client, matter-specific conflicts)

See also

Source

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