Donald Keith Thomas III
On the New York attorney register since 2025 · office in O’Fallon, IL
PlainAttorney’s reading of the public register file, not a court record.
- Registration No.
- 6290977
- Admitted
- 2025 · Third Department
- Status
- Currently registered
- Next registration
- May 2027
Donald Keith Thomas III is currently registered on the New York attorney register file of Sep 29, 2026. Admitted in 2025 in the Third Department, with an office in O’Fallon, IL; next registration due May 2027. The status is the same in all 3 files we hold.
What this status means on the register
On the register, “Currently registered” means Donald Keith Thomas III has filed the biennial registration the court system requires; the next one is due in May 2027.
- 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
The register gives this attorney’s employer as “Manning Gross & Massenburg LLP”. We count that spelling with Manning Gross + Massenburg LLP, the name most registrants give for the firm now; the register does not say where the attorney works today.
41 other attorneys list Manning Gross + Massenburg LLP or one of its other names as their employer on the register; 37 of them were admitted before 2025, and 4 of the 42 give an office in O’Fallon, IL. The 5 whose admission is closest to 2025, earliest first:
| Attorney | Admitted | Status |
|---|---|---|
| Dillon Samuel Aisenberg | 2024 | Currently registered |
| Theresa Marie Brick | 2024 | Currently registered |
| Anthony David Danhelka | 2025 | Currently registered |
| Ashley Yoora Shin | 2025 | Currently registered |
| Tess Bedingfield | 2026 | Currently registered |
All 42 registrations that list Manning Gross + Massenburg LLP
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
Donald Keith Thomas III studied at Saint Louis University School of Law (the register spells it “St. Louis University School of Law”). 59 of its 325 living graduates on the register were admitted in the 2020s, as Donald Keith Thomas III was.
- Same law school
- 325living graduates; 85.5% registered (current or due), against 87.1% overall
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 Manning Gross + Massenburg LLP42 on the register, 37 of the others admitted before 2025; 4 of the 42 give an office in O’Fallon, IL.
- Saint Louis University School of Law graduates on the register325 living, 85.5% registered; 2 of them list Manning Gross + Massenburg LLP.
- Admitted in 20259,764 people admitted in 2025 are on the register, 4,056 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 Donald Keith Thomas III’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 Donald Keith Thomas III in 2025. 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).