Tatsuya Koyama
On the New York attorney register since 2014 · office in Washington DC, DC
PlainAttorney’s reading of the public register file, not a court record.
- Registration No.
- 5262985
- Admitted
- 2014 · Third Department
- Status
- Currently registered
- Next registration
- Feb 2028
Tatsuya Koyama is currently registered on the New York attorney register file of Sep 29, 2026. Admitted in 2014 in the Third Department, with an office in Washington DC, DC; next registration due Feb 2028. The status is the same in all 3 files we hold.
What this status means on the register
On the register, “Currently registered” means Tatsuya Koyama has filed the biennial registration the court system requires; the next one is due in Feb 2028.
- Currently registered unchanged
- Currently registered unchanged
- Currently registered the first file we hold
Source: NY Office of Court Administration, attorney registration file (data.ny.gov, dataset eqw2-r5nb), downloaded Sep 29, 2026; the Jul 3, 2026 and Aug 6, 2026 files for the history.
Others who list this employer on the register
491 other attorneys list Mayer Brown LLP or one of its other names as their employer on the register; 242 of them were admitted before 2014. The 5 whose admission is closest to 2014, earliest first:
| Attorney | Admitted | Status |
|---|---|---|
| Maria Alevras-Chen | 2014 | Delinquent |
| Tal Ben Porat | 2014 | Due to re‑register |
| Benjamin Warren Bierwirth | 2014 | Currently registered |
| Karen Kawan Chong | 2014 | Due to re‑register |
| Lucas Giardelli | 2014 | Currently registered |
Source: NY Office of Court Administration, attorney registration file (data.ny.gov, dataset eqw2-r5nb), downloaded Sep 29, 2026; employer spellings merged (methodology).
Where this record sits on the register
Tatsuya Koyama studied at University of Chicago Law School (the register spells it “THE UNIVERSITY OF CHICAGO LAW SCHOOL”). 868 of its 3,232 living graduates on the register were admitted in the 2010s, as Tatsuya Koyama was.
- Same law school
- 3,232living graduates; 87.4% registered (current or due), against 87.1% overall
- Office in Washington DC, DC
- 39living registrants (outside New York State)
Of the 39 living registrants with an office in Washington DC, DC, 21 were admitted before 2014 and 15 after.
Source: NY Office of Court Administration, attorney registration file (data.ny.gov, dataset eqw2-r5nb), downloaded Sep 29, 2026; living registrants only.
Questions this record leads to
- Everyone who lists Mayer Brown LLP492 on the register, 242 of the others admitted before 2014.
- University of Chicago Law School graduates on the register3,232 living, 87.4% registered.
- New York-admitted attorneys in Washington DC, DC39 living registrants give an office there.
- Admitted in 201410,747 people admitted in 2014 are on the register, 4,172 of them through the Third Department.
- Every registration that reads “Currently registered”286,911 on the register file of Sep 29, 2026, by decade of admission.
- What a New York lawyer may chargeThe court rules on fees, retainers and fee disputes, each cited.
How to confirm it officially
For a statement of Tatsuya Koyama’s standing, contact the Attorney Registration Unit of the NY Office of Court Administration (nycourts.gov/attorneys), or ask the Appellate Division, Third Department, which admitted Tatsuya Koyama in 2014. The register places the office outside New York, so a complaint would go to that department’s grievance committee (22 NYCRR 1240.7(a)(2)).
This page reads the register file of Sep 29, 2026, and the court system’s own search can be newer; the register shows only the current value, so a suspension that ended before the files we hold, or a censure, leaves no trace here (Appellate Division decisions are published through the court system’s Law Reporting Bureau).