Examiner Tom Y Chang has allowed 261 of 475 decided applications.
Tom Y Chang maintains a public record across hundreds of decided applications in Technology Center 2400, spanning three art units. His pooled allowance rate is 55%, meaning that across his decided applications, allowances and abandonments combined, 55% resulted in allowance. The allowance rate ranges from 45% to 86% across these art units, reflecting variation in outcomes by subject matter and art unit. This pooled figure represents his aggregate record and is not a prediction of any specific application's outcome.
A pooled record aggregates data across multiple art units and therefore describes past outcomes in the aggregate, not in any individual art unit or for any specific application. The overall allowance rate reflects historical decisions across all of an examiner's art units combined. Pooled figures are descriptive of past record only and are not predictions about how any particular application will be examined or decided.
These are aggregate statistics from this examiner's past public record — not predictions about any specific application. The per-art-unit figures below show how the record varies across art units. Our approach to patent prosecution →
Each section benchmarks this examiner against that art unit's average. Figures are this examiner's own public record within the art unit; the overall rate above pools them.
Grounds can co-occur, so the four don't sum to 100%. The art-unit figure is the unweighted mean across examiners in the art unit; §102 and §112 carry no art-unit benchmark.
Allowance rate for applications with an examiner interview versus without one.
A correlation, not proof that interviews cause allowances. Based on 158 decided applications with an interview and 166 without.
Grounds can co-occur, so the four don't sum to 100%. The art-unit figure is the unweighted mean across examiners in the art unit; §102 and §112 carry no art-unit benchmark.
Allowance rate for applications with an examiner interview versus without one.
A correlation, not proof that interviews cause allowances. Based on 65 decided applications with an interview and 57 without.
Grounds can co-occur, so the four don't sum to 100%. The art-unit figure is the unweighted mean across examiners in the art unit; §102 and §112 carry no art-unit benchmark.
Lynch LLP represents applicants in patent prosecution before the USPTO. These are general resources about the firm's services — not advice about this examiner or any specific application.
Methodology. This page pools every art unit in which Examiner Tom Y Chang has a public record within Technology Center 2400. Statistics are computed from publicly available USPTO records, refreshed on a recurring schedule. This page's data was last updated July 22, 2026. The overall allowance rate is total allowed divided by total decided applications (allowed plus abandoned) across all art units — not an average of the per-art-unit rates; pending applications are excluded. Figures are rounded for display. Pooled sample: 507 applications.
Rejection rates. Each §-rate is the share of this examiner's applications that drew at least one office-action rejection in which that statutory ground appears; applications with no rejection on record are excluded, and because grounds can co-occur the four do not sum to 100%. The art-unit figure beside each is the unweighted mean of the per-examiner rates across the art unit, published for §101 and §103 only. Beside the overall allowance rate we show a benchmark: for a single-art-unit examiner it is exactly that art unit's average, labeled “art-unit average”; for an examiner spanning several art units it is the “weighted peer average” — the per-art-unit averages, weighted by this examiner's application count in each — labeled distinctly because it is a blended figure, not any single art unit's average. Both are built from the same per-art-unit averages the panels show.
Lynch LLP is not affiliated with, endorsed by, or sponsored by the United States Patent and Trademark Office. Examiner statistics are derived from publicly available USPTO data.
These statistics describe past examiner behavior and do not predict the outcome of any particular application. Past results do not guarantee future outcomes. Where this page compares an examiner's allowance rate to an art-unit average, that comparison is a factual description of the public record, not a characterization of any individual examiner's conduct or competence.
This page is for general informational purposes and is not legal advice. No attorney-client relationship is formed by viewing it. Full disclaimers →
ATTORNEY ADVERTISING — Sean Lynch, Partner, Lynch LLP