Examiner Mark Hatzilambrou
Grant ratio: 59.7% (28th percentile in Art Unit 2891 among examiners with at least 20 applications). Average office actions per grant: 2.80. Most common rejection type: §103.
Appears inactive
Last office action in data: October 2023
Examiner record
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| Group | Examiners | Average grant ratio | Average office actions / grant |
|---|---|---|---|
| Art Unit | 28 | 55.9% | 1.85 |
| Group | 288 | 53.7% | 1.76 |
| 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 | 0 | 0.0% |
| 1 OA | 73 | 25.7% |
| 2 OAs | 89 | 31.3% |
| 3 OAs | 31 | 10.9% |
| 4 OAs | 36 | 12.7% |
| 5+ OAs | 55 | 19.4% |
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 |
|---|---|---|---|
| 2013 | 16 | 3 | 18.8% |
| 2014 | 21 | 9 | 42.9% |
| 2015 | 22 | 6 | 27.3% |
| 2016 | 30 | 19 | 63.3% |
| 2017 | 29 | 11 | 37.9% |
| 2018 | 27 | 17 | 63.0% |
| 2019 | 33 | 21 | 63.6% |
| 2020 | 16 | 11 | 68.8% |
| 2021 | 11 | 9 | 81.8% |
| 2022 | 32 | 28 | 87.5% |
| 2023 | 36 | 29 | 80.6% |
Rejections by office-action stage
| Office-action stage | Actions observed | §101 | §102 | §103 | §112 |
|---|---|---|---|---|---|
| Action 1 | 284 | 0.0% | 5.6% | 87.7% | 6.7% |
| Action 2 | 211 | 0.0% | 3.8% | 91.5% | 3.8% |
| Action 3 | 122 | 0.0% | 4.1% | 93.4% | 2.5% |
| Action 4 | 91 | 0.0% | 3.3% | 94.5% | 2.2% |
| Action 5 | 55 | 0.0% | 3.6% | 92.7% | 3.6% |
| Action 6 | 31 | 0.0% | 6.5% | 93.5% | 0.0% |
| Action 7 | 17 | 0.0% | 5.9% | 94.1% | 0.0% |
| Action 8 | 11 | 0.0% | 0.0% | 100.0% | 0.0% |
| Action 9 | 3 | 0.0% | 0.0% | 100.0% | 0.0% |
| Action 10 | 2 | 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%
0.0%
0.0%
2019: PEG
0.0%
0.0%
0.0%
0.0%
0.0%
Each bar is the percentage of office actions with a §101 rejection.
PTAB appeals
Matched decisions: 4. Merits outcomes: 3 affirmed, 0 affirmed in part, and 1 reversed.
- Full reversal rate
- 25.0% 1/4 decisions
- Full or partial reversal rate
- 25.0% 1/4 decisions
- Median appeal duration
- 12.6 months
- New grounds of rejection
- 0
Recent decisions
| Decision | Application | Outcome | Issues |
|---|---|---|---|
| Dec. 16, 2021 | 16/034,385 | Reversed | §103 |
| Mar. 22, 2021 | 15/493,735 | Affirmed | §103 |
| Jan. 21, 2021 | 15/507,889 | Affirmed | §103 · §112 |
| Jan. 8, 2019 | 13/844,270 | Affirmed | §103 |
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.