Maria Isabel Bacay, MD
NPI 1679599070ActiveIndividual· Internal Medicine· Manteca, CA
Internal Medicine (MD) with Bacay-Aruiza Medical Associates Inc, practicing in Manteca, California. Their prescriptions cost Medicare Part D more than their services did: $1,529,171 for 11,856 claims, against $103,907 paid for services in 2024. Bayer Healthcare Pharmaceuticals Inc. was the largest of 19 companies reporting payments in 2025, $1,470 in all, mostly food and beverage. Lists Doctors Hospital of Manteca and 1 other hospital as hospital affiliations.
Overview
| NPI | 1679599070 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MD |
| Sole proprietor | No |
| NPI issued | Jul 15, 2006 |
| Last updated in NPPES | Jan 2, 2008 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine Primary | 207R00000X | A51759 | CA |
Exclusion screening
| List | Result | Details |
|---|---|---|
| HHS-OIG LEIE · Oct 9, 2026 | No match | Checked by NPI and by name + state |
| North Carolina Medicaid · Nov 4, 2026 | No match | — |
| New York OMIG · Nov 4, 2026 | No match | — |
| Ohio Medicaid · Nov 4, 2026 | No match | — |
| Pennsylvania Medicheck · Nov 4, 2026 | No match | — |
| Washington HCA · Nov 4, 2026 | No match | — |
Official OIG search · How matching works ·Bulk check a roster
Medicare
| Enrollment (PECOS) | Enrolled Practitioner - Internal Medicine (CA) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 229 |
|---|---|
| Services billed | 1,976 across 37 procedure codes |
| Paid by Medicare | $103,907 |
Part D prescriptions in 2024
| Prescriptions (claims) | 11,856 · 25,682 30-day fills |
|---|---|
| Patients | 792 |
| Total drug cost | $1,529,171 |
| Generic share | 82% of claims |
Education and affiliations
| Graduation year | 1985 |
|---|---|
| Medicare specialty | Internal Medicine |
| Telehealth | Offers telehealth |
Medical group
- Bacay-Aruiza Medical Associates IncManteca, CA · 3 clinicians
Hospital affiliations
- Doctors Hospital of MantecaManteca, CA
- Sutter Tracy Community HospitalTracy, CA
Other facilities
- Home Care for the 21st Century StocktonHome health agency · Stockton, CA
- Lifeguard Home HealthHome health agency · Pleasanton, CA
- Prohealth Home Care, IncHome health agency · Stockton, CA
- Lifeguard Hospice Care, IncHospice · Pleasanton, CA
Industry payments (Open Payments)
- 2025$1,470 · 68 payments from 19 companies
- 2024$1,290 · 62 payments from 17 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Bayer Healthcare Pharmaceuticals Inc. | $305.11 | 9 |
| Boehringer Ingelheim Pharmaceuticals, Inc. | $194.87 | 6 |
| Astrazeneca Pharmaceuticals LP | $179.85 | 13 |
| Eisai Inc. | $118.57 | 7 |
| Vanda Pharmaceuticals Inc. | $89.72 | 4 |
What the 2025 payments were for
- Food and Beverage$1,450 · 67 payments
- Education$20.22 · 1 payment
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
Other Internal Medicine providers in Manteca
- 1760459416
- 1952586067
- 1437113065
- 1336324458
- 1841471166
- 1306741392
- 1306924212
- 1629094032
- 1760594105
- 1336725159
- 1528049988
- 1750021788