Mariko Ishiyama, D.O
NPI 1952662991 · Hospitalist Physician · Modesto, CA
Enrolled with Medicare as Practitioner - Hospitalist · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Mariko Ishiyama, D.O is a Hospitalist Physician provider in Modesto, CA (NPI 1952662991).
Provider details
- NPI number
- 1952662991
- Entity type
- Individual
- Primary specialty
- Hospitalist PhysicianAllopathic & Osteopathic Physicians
- Credential
- D.O
- Sex
- Female
- Sole proprietor
- Yes
- License
- 20A13309 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
14 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)28% of score
203 Medicare services, 2024 (ranked within specialty)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Initial Hospital Care With Moderate Level of Medical Decision Making, If Using Time, at Least 75 Minutes99223 | 161 | $192 |
| Initial Hospital Care With Straightforward Or Low-Level Medical Decision Making, If Using Time, at Least 55 Minutes99222 | 29 | $144 |
| Hospital Discharge Day Management, More Than 30 Minutes99239 | 13 | $115 |
Typical Medicare-allowed amounts for these services range $115–$192 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
Practice location
Mailing address
Registry dates
- Enumerated
- 2012-06-06
- Last updated
- 2024-08-14
- Certified
- 2024-08-14
Frequently asked questions
- What is Mariko Ishiyama's NPI number?
- Mariko Ishiyama's National Provider Identifier (NPI) is 1952662991, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mariko Ishiyama's specialty?
- Mariko Ishiyama is listed in the NPPES registry with a primary specialty of Hospitalist Physician (Allopathic & Osteopathic Physicians).
- Where is Mariko Ishiyama located?
- Mariko Ishiyama's practice location on file with NPPES is 1441 Florida Ave, Modesto, CA 95350-4404.
- What is Mariko Ishiyama's phone number?
- The practice phone number listed in the NPPES registry for Mariko Ishiyama is (209) 576-3525.
- Does Mariko Ishiyama accept Medicare?
- Mariko Ishiyama is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Mariko Ishiyama's NPI active?
- Yes — Mariko Ishiyama's NPI (1952662991) is active in the NPPES registry as of the last update on 2024-08-14.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.