New York attorney record · Judicial Dept 3
Mark Andrew Costello
Nova Southeastern University Shepard Broad Law Center alumna, admitted to the New York bar in 2021, registered office in Hartsdale, NY. This record's status, address, and registration history come straight from the NY Office of Court Administration.
- 2021
- Admitted
- 5
- Years in bar
- 5862883
- NY reg #
The record in one line
Admitted in 2021, Mark Andrew Costello has built 5 years of active New York practice - more tenure than 12% of the state's currently-active attorneys.
- 5 yrs
- in active practice since admission
- Active
- current bar status: "Currently registered"
- Top 88%
- by tenure among active NY attorneys
- Law school
- Nova Southeastern University Shepard Broad Law Center
Data updated May 2026
What this profile tells you
Bar status & tenure
Bar number 5862883 on the New York register belongs to Mark Andrew Costello, currently in active standing. Registration is recorded within Judicial Department 3, the appellate division overseeing this attorney's home district.
Practice context & education
Practice address is listed under The Costello Law Firm, P.A., located in Hartsdale, NY (Westchester County), ZIP 10530. Educational background: Nova Southeastern University Shepard Broad Law Center (255 registered alumni).
State context & due diligence
Mark Andrew Costello is currently part of the New York bar's active cohort, a group the breakdown below sizes against the full register.
Experience vs. the active New York bar
5 years into an active New York practice since a 2021 admission, Mark Andrew Costello sits here on the statewide experience curve - taller bars hold more attorneys at that experience level.
5 years on the New York bar
Years since admission, all currently-active NY attorneys
5 Top 88% higher than 12% of 284,296 active NY attorneys
Each bar is a band; taller bars hold more active NY attorneys. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.
Source NY Office of Court Administration, Attorney Registration · May 2026
How Mark compares to fellow Nova Southeastern University Shepard Broad Law Center alumni
Among the 212 Nova Southeastern University Shepard Broad Law Center graduates in the New York register, Mark Andrew Costello is longer-tenured than 23% - a school-cohort view of experience, alongside the statewide one above.
5 years vs. Nova Southeastern University Shepard Broad Law Center alumni
Years since admission - 212 NY-registered alumni of this school
5 Top 77% higher than 23% of 212 fellow alumni
Each bar is a band; taller bars hold more fellow alumni. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.
Source NY Office of Court Administration, Attorney Registration · May 2026
Nova Southeastern University Shepard Broad Law Center's active-bar rate
Of Nova Southeastern University Shepard Broad Law Center's 255 alumni in the New York register, 82.9% currently hold "Currently registered" status, above the statewide average.
Nova Southeastern University Shepard Broad Law Center alumni, active-bar rate
The 2021 admission class today
Of the 7,829 attorneys admitted to the New York bar in 2021, 93.8% are still "Currently registered" today, above the statewide average across all admission years.
Professional Details
- Status
- Currently registered
- Registration Number
- 5862883
- Year Admitted
- 2021 (5 yrs · mid-career)
- Judicial Department
- 3
- Next Registration
- Jul 2027
Location & Contact
- Company
- The Costello Law Firm, P.A.
- City
- Hartsdale, NY
- County
- Westchester
- ZIP Code
- 10530
- Phone
- (954) 560-3038
Status Distribution Across the New York Bar
Mark Andrew Costello's current status, "Currently registered", places this attorney in the 66.2% of the 429,620-attorney New York register currently marked active.
Full statewide breakdown & source note
Source: NY Office of Court Administration, Attorney Registrations. Status counts reflect the latest reporting cycle. Bar status confirms registration only; it does not imply competence, specialty fit, or freedom from complaints.
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Compare attorneys →Before you rely on this record
Mark Andrew Costello's "Currently registered" listing confirms bar standing only, it is a registration fact to verify, not a verdict on quality or competence.
Frequently Asked Questions
Where is Mark Costello licensed?
Mark Costello is licensed to practice law in New York.
When was Mark Andrew Costello admitted to the bar?
Mark Andrew Costello has been on the New York bar register since 2021.
Where did Mark Andrew Costello go to law school?
Mark Andrew Costello attended Nova Southeastern University Shepard Broad Law Center.
What company does Mark Andrew Costello work for?
Mark Andrew Costello is associated with The Costello Law Firm, P.A. in Hartsdale, NY.
Is Mark Andrew Costello in good standing?
Yes, Mark Andrew Costello holds active bar status ("Currently registered").
Sourced from the NY Office of Court Administration, informational only, not legal advice. Full disclosure.
Read our methodology - how this data is sourced, computed, and verified.