Marissa Wat, RN, MSN
NPI 1023411642 · Certified Registered Nurse Anesthetist · San Francisco, CA
Enrolled with Medicare as Practitioner - Certified Registered Nurse Anesthetist (crna) · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Marissa Wat, RN, MSN is a Certified Registered Nurse Anesthetist provider in San Francisco, CA (NPI 1023411642).
Provider details
- NPI number
- 1023411642
- Entity type
- Individual
- Primary specialty
- Certified Registered Nurse AnesthetistPhysician Assistants & Advanced Practice Nursing Providers
- Credential
- RN, MSN
- Sex
- Female
- Sole proprietor
- No
- License
- 639926 (CA)
Specialties & taxonomies
Physician Assistants & Advanced Practice Nursing Providers
Nursing Service Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
11 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
256 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
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 .
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) |
|---|---|---|
| Anesthesia for Other Procedure on Large Bowel Using an Endoscope00811 | 97 | $115 |
| Anesthesia for Exam of Colon Using an Endoscope00812 | 69 | $95 |
| Anesthesia for Other Procedure on Esophagus, Stomach, Or Upper Small Bowel Using an Endoscope00731 | 66 | $126 |
| Anesthesia for Procedure on Small and Large Bowel Using an Endoscope00813 | 24 | $152 |
Typical Medicare-allowed amounts for these services range $95–$152 (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.
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$96 across 4 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2014-09-28
- Last updated
- 2015-11-05
Frequently asked questions
- What is Marissa Wat's NPI number?
- Marissa Wat's National Provider Identifier (NPI) is 1023411642, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Marissa Wat's specialty?
- Marissa Wat is listed in the NPPES registry with a primary specialty of Certified Registered Nurse Anesthetist (Physician Assistants & Advanced Practice Nursing Providers).
- Where is Marissa Wat located?
- Marissa Wat's practice location on file with NPPES is 505 Parnassus Ave, San Francisco, CA 94143-2204.
- What is Marissa Wat's phone number?
- The practice phone number listed in the NPPES registry for Marissa Wat is (415) 476-9000.
- Does Marissa Wat accept Medicare?
- Marissa Wat is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Marissa Wat's NPI active?
- Yes — Marissa Wat's NPI (1023411642) is active in the NPPES registry as of the last update on 2015-11-05.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.