This educational guide is based on the linked primary sources. It is not a Court publication, is not affiliated with the Court, and is not legal advice.
In brief
Overview
The case concerns how the Social Security Administration determines disability eligibility, focusing on the criteria at step four (previous work) and step five (age factor).
According to Petitioner, the Commissioner’s longstanding construction requires that a claimant be unable to perform previous work and also be unable to engage in any other substantial gainful work given age, education, and experience.
According to Petitioner (Jeffrey A. Lamken), according to Petitioner (Jeffrey A. Lamken), according to Petitioner (Jeffrey A. Lamken), according to Petitioner (Jeffrey A. Lamken), petitioner argues that step four is a measure of severity and that the Commissioner’s construction has been consistently applied for decades, affecting millions of claims.
Respondent contends that at step four, age, education, and prior work experience are not considered.
The case raises questions about whether the regulations are ambiguous and whether the Commissioner’s interpretation is reasonable.
- [1] 6f7b5188f4a96cf6988f-r1-6f5980bc6560075a.pdf, p. 3
- [2] 6f7b5188f4a96cf6988f-r1-6f5980bc6560075a.pdf, p. 13
- [3] 6f7b5188f4a96cf6988f-r1-6f5980bc6560075a.pdf, p. 3
- [4] 6f7b5188f4a96cf6988f-r1-6f5980bc6560075a.pdf, p. 36
- [5] 6f7b5188f4a96cf6988f-r1-6f5980bc6560075a.pdf, p. 39
- [6] 6f7b5188f4a96cf6988f-r1-6f5980bc6560075a.pdf, p. 13
- [7] 6f7b5188f4a96cf6988f-r1-6f5980bc6560075a.pdf, p. 22
- [8] 6f7b5188f4a96cf6988f-r1-6f5980bc6560075a.pdf, p. 22
Background and question before the Court
According to Justice O'Connor, justice O'Connor questioned how circuits and judges view the regulation’s ambiguity and reasonableness.
What each side argues
Petitioner (Commissioner of Social Security)
According to Petitioner, the Commissioner’s construction requires two conditions: inability to perform previous work and inability to perform any other substantial gainful work given age, education, and experience.
According to Petitioner (Jeffrey A. Lamken), according to Petitioner (Jeffrey A. Lamken), according to Petitioner (Jeffrey A. Lamken), according to Petitioner (Jeffrey A. Lamken), step four (previous work) is a measure of severity; the claimant must be unable to do previous work.
Respondent (Pauline Thomas)
According to Respondent, at step four, age, education, and prior work experience are not factors in the disability determination.
What happened at oral argument
According to Petitioner (Jeffrey A. Lamken), according to Petitioner (Jeffrey A. Lamken), according to Petitioner (Jeffrey A. Lamken), according to Petitioner (Jeffrey A. Lamken), the oral argument featured extensive discussion of step four as a severity measure and the long‑standing application of the Commissioner’s construction.
The parties debated whether the regulations are ambiguous and whether the Commissioner’s interpretation is reasonable.
What the Court decided
Why it matters
The interpretation of the disability eligibility rules affects millions of claimants and has been applied to approximately 200,000 step‑four denials each year.
Terms to know
No glossary terms are available for this guide.
Primary sources
Read the source materials on the official site or open the immutable repository copy used for this guide.
- 6f7b5188f4a96cf6988f-r1-6f5980bc6560075a.pdforal argument transcript
Guide generated September 20, 2026. Automated validation accepted this version.