Examiner Sung Il Cho
Grant ratio: 78.8% (47th percentile in Art Unit 2825 among examiners with at least 20 applications). Average office actions per grant: 1.99. Most common rejection type: §103.
Recently active
Last office action in data: August 2026
Examiner record
- Examiner ID
- 91558
- Primary art unit
- 2825
- Work group
- 2820
- Technology center
- 2800
- Applications
- 638
- Granted applications
- 503
- Examiner phone
- (571) 270-0137
- Supervisor
- Alexander G Sofocleous
- Supervisor phone
- (571) 272-0635
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| Group | Examiners | Average grant ratio | Average office actions / grant |
|---|---|---|---|
| Art Unit | 21 | 60.8% | 1.48 |
| Group | 207 | 71.2% | 1.64 |
| Tech Center | 2,413 | 62.4% | 1.69 |
| USPTO | 16,475 | 52.7% | 1.98 |
Office actions per application
| Office actions | Applications | Share of applications |
|---|---|---|
| No OA observed | 8 | 1.3% |
| 1 OA | 269 | 42.2% |
| 2 OAs | 224 | 35.1% |
| 3 OAs | 79 | 12.4% |
| 4 OAs | 33 | 5.2% |
| 5+ OAs | 25 | 3.9% |
Each application is counted once. “5+” includes all higher counts.
Grant history
Recent ratios may be lower while applications remain pending.
Yearly counts
| Year | Applications | Grants | Grant rate |
|---|---|---|---|
| 2015 | 45 | 36 | 80.0% |
| 2016 | 40 | 34 | 85.0% |
| 2017 | 54 | 44 | 81.5% |
| 2018 | 54 | 48 | 88.9% |
| 2019 | 54 | 50 | 92.6% |
| 2020 | 58 | 56 | 96.6% |
| 2021 | 53 | 52 | 98.1% |
| 2022 | 45 | 42 | 93.3% |
| 2023 | 51 | 44 | 86.3% |
| 2024 | 64 | 64 | 100.0% |
| 2025 | 59 | 33 | 55.9% |
| 2026 | 61 | 0 | 0.0% |
Rejections by office-action stage
| Office-action stage | Actions observed | §101 | §102 | §103 | §112 |
|---|---|---|---|---|---|
| Action 1 | 630 | 0.2% | 7.9% | 85.1% | 1.6% |
| Action 2 | 361 | 0.3% | 46.0% | 45.4% | 3.0% |
| Action 3 | 137 | 0.7% | 40.9% | 48.2% | 2.2% |
| Action 4 | 58 | 0.0% | 41.4% | 44.8% | 6.9% |
| Action 5 | 25 | 0.0% | 36.0% | 56.0% | 4.0% |
| Action 6 | 15 | 0.0% | 46.7% | 46.7% | 6.7% |
| Action 7 | 9 | 0.0% | 11.1% | 88.9% | 0.0% |
| Action 8 | 6 | 0.0% | 16.7% | 66.7% | 0.0% |
| Action 9 | 3 | 0.0% | 0.0% | 100.0% | 0.0% |
| Action 10 | 3 | 0.0% | 0.0% | 100.0% | 0.0% |
Section 101 rejections
Last 3 years: 2023-08-28–2026-08-28. All years includes every dated office action in the data.
By year
0.0%
0.0%
2014: Alice
0.0%
0.0%
0.0%
1.1%
0.9%
2019: PEG
0.0%
0.0%
0.0%
0.0%
0.0%
2024: AI examples
1.0%
2025: August memo
0.0%
0.0%
Each bar is the percentage of office actions with a §101 rejection.
PTAB appeals
Matched decisions: 3. Merits outcomes: 1 affirmed, 0 affirmed in part, and 2 reversed.
- Full reversal rate
- 66.7% 2/3 decisions
- Full or partial reversal rate
- 66.7% 2/3 decisions
- Median appeal duration
- 21.7 months
- New grounds of rejection
- 0
Recent decisions
| Decision | Application | Outcome | Issues |
|---|---|---|---|
| Jun. 17, 2024 | 16/386,490 | Reversed | §102 · §112 |
| Dec. 18, 2019 | 13/196,042 | Reversed | §103 · §112 |
| Nov. 21, 2019 | 14/083,637 | Affirmed | §103 · §112 |
The examiner match uses the last recorded office action before the decision. Reversal rates exclude rehearings, remands, dismissals, and other decisions that did not reach the merits. Data through Aug. 27, 2026.