SO Calif Regional Service Office of Narcotics Anonymous
Donations deductibleRevenue
$63k
year to 31 December 2025
Expenses
$61k
year to 31 December 2025
Total assets
$177k
$67k liabilities
Net assets
$110k
assets less liabilities
Directors and trustees
5
5.0 years on average
Staff
1
employees, year to 31 December 2025
Chair observed
≥1 yr
Mark Larsen
Left since last filing
0
no seats appear to have opened
SO Calif Regional Service Office of Narcotics Anonymous' network
5 people3 organisationsi5 people and 3 organisations on this map.The large node is the subject of this page. Solid lines are what the register itself records (5). Violet dotted lines (3) are likely: the same full name sits on the current board of another organisation in the same register and region. Form 990 filings give names without a person identifier; SEC insider filings carry a CIK. It may be a different person.The board
5 listediTime on the board is observed from the annual filings: the IRS files no appointment date, so the bar counts years from the first filing the person appears on - a lower bound, not a filed start date. Names are exactly as filed. The IRS publishes no person identifier, so this edition does not yet link a person across organisations in the tables. The network map shows same-name matches as likely links only, never as confirmed.Time served and departures are observed across annual filings. Observed time served is a lower bound - a member may have joined before the first year on record. The organisation reported 16 voting members of its governing body on its latest Form 990 Part VI; we list 5 in Part VII (Part VII does not always name every voting member).| Name | Role as filed | Since | On the board |
|---|---|---|---|
| Mark Larsen Chair | Chairperson | 2024 | 2 yrs |
| Kenneth Mason (also filed as Ken Mason, Ken Mason) | Office Manager | 2018 | 8 yrs |
| Sophia Possidon | Vice Chairperson | 2023 | 3 yrs |
| Thomas Thompson | Company secretary | 2024 | 2 yrs |
| Vicki Guadalupe | Controller | 2018 | 8 yrs |
Under 5 years5 to 6 years6 years or more
Officers and senior leadership
8 listediNamed in Part VII as officers, key employees or highest-compensated staff - not board members, shown for completeness.| Name | Title as filed | On the filings |
|---|---|---|
| Chuck Tuma | Chairperson | 2022 |
| Mark Larsen | Vice-Chairperson | since 2018 |
| Martin Barbeau | Special Worker | since 2019 |
| Sophia Possidon | Assistant Treasurer | 2022 |
| Shawna Hernandez | Company secretary | 2018 |
| Sophia Possidon-Casey | Vice-Chairperson | since 2018 |
| Thomas Thompson | Company secretary | since 2022 |
| Vicki Guadalupe | Treasurer | since 2019 |
Pay and hours
year to 31 December 2025iFrom Part VII of the Form 990: compensation reported for each officer, director, trustee, key employee and highest-paid staff member, and the average hours a week they report. Most board members are unpaid; a blank means nothing was reported. Pay from related organisations is shown separately.| Name | Title as filed | Hours a week | Pay from the organisation | Related organisations | Other |
|---|---|---|---|---|---|
| Mark Larsen | Chairperson | 30 | $0 | ||
| Vicki Guadalupe | Controller | 10 | $0 | ||
| Thomas Thompson | Secretary | 10 | $0 | ||
| Sophia Possidon | Vice Chairperson | 10 | $0 | ||
| Ken Mason | Office Manager | 10 | $0 |
No pay was reported for anyone in Part VII on this return.
About
- Legal name
- So Calif Regional Service Office of Narcotics Anonymous
- EIN
- 954094844
- Address
- 1937 S Myrtle Ave, Monrovia, CA, 91016-4855
- State
- California
- Mission
- Provide educational material to recovering addicts (as filed on the Form 990)
- Activity (NTEE)
- F50 Mental health and crisis intervention
- IRS classification
- 501(c)03 (tax-exempt under section 501(c)(3) where shown)
- Classified purpose
- Mental Health & Crisis Intervention
- Size band
- 4 (IRS master file code)
- Formed
- 1986
- Principal officer
- Mark Larsen (as named on the Form 990)
- IRS ruling date
- 1 June 1989
- Status
- Code 01 (unconditional exemption)
- Form 990 filings on record
- 7, latest 2025
- IRS Publication 78
- PC (contributions deductible)
Most connected
Longest observed on the filings
≥8years on the filingsKenneth Mason
≥8years on the filingsVicki Guadalupe
≥3years on the filingsSophia Possidon
≥2years on the filingsMark Larsen
Latest return
year to 31 December 2025iFigures from the newest Form 990 or 990-EZ in the IRS e-file releases of 2025 and 2026, for the year ending 31 December 2025. US dollars, as filed.- Total assets
- $177k
- Total liabilities
- $67k
- Net assets or fund balances
- $110k
- Contributions and grants received
- $0
- Program service revenue
- $0
- Employees
- 1
Filed finances
1 yeariTotals as filed on the IRS Form 990 (revenue and expenses), by tax year.| Tax year | Total revenue | Total expenses | Surplus or deficit |
|---|---|---|---|
| 2024 | $33k | $81k | Deficit $48k |
As filed on the IRS Form 990. US dollars.