Karen Marcus, M.D.
Karen Marcus, M.D. is a Psychiatry Physician in Pittsburg, CA, registered under NPI 1003043993.
Getting there
Here is what surrounds this office in Pittsburg, based on OpenStreetMap data collected Sep 1, 2026. Parking is available about 381 ft away. The nearest transit stop is 707 ft away, served by Loveridge Road & Loveridge Circle. A pharmacy sits 0.24 mi from the entrance (Walmart Pharmacy), which helps if you leave with a prescription. If you arrive early, there is a coffee shop 0.30 mi away.
Getting here and what is nearby
Parking 224 ft ~1 min
Parking 295 ft ~2 min
Parking 381 ft ~2 min
Transit East Leland Road & Loveridge Road 658 ft ~3 min
Transit East Leland Road & Loveridge Road 675 ft ~3 min
Transit Loveridge Road & Loveridge Circle 707 ft ~3 min
Restaurant Popeyes 720 ft ~3 min
1283 East Leland Road, Pittsburg 94565
10:00-22:00
Convenience ampm 829 ft ~4 min
Gas station Shell 845 ft ~4 min
Convenience Shell 909 ft ~4 min
Gas station Arco 883 ft ~4 min
Restaurant Wendy's 0.20 mi ~4 min
2243 Loveridge Road, Pittsburg 94565
09:00-22:00
Restaurant IHOP 0.20 mi ~4 min
2290 Loveridge Road, Pittsburg 94565
Pharmacy Walmart Pharmacy 0.24 mi ~5 min
Coffee iTea 0.30 mi ~6 min
Convenience 7-Eleven 0.33 mi ~7 min
Hotel Hampton Inn & Suites Pittsburg 0.51 mi ~11 min
Distances are straight‑line estimates — walking routes may be longer. Hours and phone numbers can change; call ahead to confirm.
Credentials and Medicare
| Licence | State | Specialty |
|---|---|---|
| A108365 | CA | Psychiatry Physician primary |
This provider holds licence A108365 issued in CA. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.
- Status
- Approved
- Provider type
- Practitioner - Psychiatry
- PAC ID
- 8921271289
- Enrollment ID
- I20111101000690
Medicare enrolment is recorded as approved under the provider type Practitioner - Psychiatry. Being enrolled means the provider can bill Medicare; it does not tell you whether they are currently accepting new Medicare patients. Call the office to confirm.
What Psychiatry covers
A Psychiatrist specializes in the prevention, diagnosis, and treatment of mental disorders, emotional disorders, psychotic disorders, mood disorders, anxiety disorders, substance-related disorders, sexual and gender identity disorders and adjustment disorders. Biologic, psychological, and social components of illnesses are explored and understood in treatment of the whole person. Tools used may include diagnostic laboratory tests, prescribed medications, evaluation and treatment of psychological and interpersonal problems with individuals and families, and intervention for coping with stress, crises, and other problems. NUCC Health Care Provider Taxonomy, code 2084P0800X
The taxonomy records how the provider classifies their own practice. It does not confirm which conditions they currently treat, whether they are accepting new patients, or which insurance they take — call the office for that.
Full NPPES record
An NPI-1 identifies a single person. It stays with the clinician for life, even if they move practice or change state, which is why the address on file can lag behind where they actually work today.
| NPI | 1003043993 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Jun 17, 2009 |
| Last updated | Mar 20, 2012 |
| Status | Active |
| Sole proprietor | No |
| Gender | Female |
| Credential | M.D. |
| Practice address |
2311 LOVERIDGE RD 2ND FLOOR Pittsburg, CA 94565 (925) 431-2600 Fax (925) 431-2665 |
Number check
How the check works, step by step
Every NPI carries a Luhn check digit — the same scheme used on credit cards. CMS prefixes the number with 80840 before computing it, which marks it as a US health identifier.
| Digit | 8 | 0 | 8 | 4 | 0 | 1 | 0 | 0 | 3 | 0 | 4 | 3 | 9 | 9 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 0 | 0 | 3 | 0 | 4 | 6 | 9 | 9 |
Sum = 57 · next multiple of 10 = 60 · check digit = 3 · actual last digit = 3
A valid check digit only means the number is well-formed. It does not mean the provider is licensed, active, or in good standing — those are separate questions answered by the sections above.