DR. JOHN D MERWIN MD
NPI 1770562209
Anesthesiology in Saint Louis, MO
About Dr. John D Merwin Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. JOHN D MERWIN MD (NPI 1770562209) is an individual anesthesiology provider in Saint Louis, Missouri, licensed in Missouri (100344) and active in the NPI registry since January 2006. He is enrolled in Medicare PECOS, is affiliated with Ssm Health Saint Louis University Hospital, and is a graduate of University Of Texas Medical School At San Antonio (1985).
NPPES Registry Identity
Specialties & Licenses
Other Identifiers 3
Accepted Insurance
Medicare Participation & PECOS CMS
Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.
Medicare Enrollment Status
Enrolled in Medicare and accepts Medicare assignment
Dr. John D Merwin Md is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.
Medicare Billing Reassignments
4Medicare enrollment records show John Merwin reassigns Medicare billing to 4 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Chesterfield, MO 63017
- Reassigned Medicare billing, Missouri enrollment
- 35 clinicians in this Medicare group
Saint Louis, MO 63110
- Reassigned Medicare billing, Missouri enrollment
- 142 clinicians in this Medicare group
Saint Louis, MO 63104
- Reassigned Medicare billing, Missouri enrollment
- 1,294 clinicians in this Medicare group
St Louis, MO 63118
- Reassigned Medicare billing, Missouri enrollment
- 25 clinicians in this Medicare group
Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.
Areas of Expertise CMS Part B claims 2
Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.
Hospital Affiliations CMS Care Compare
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
Ssm Health Saint Louis University Hospital
Acute Care Hospitals · Saint Louis, MOMedicare Quality Performance CMS QPP · MIPS
Performance in the CMS Quality Payment Program: the MIPS final score across four weighted categories, and the individual quality measures reported to Medicare.
Frequently Asked Questions NPPES & CMS
Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.
What is John Merwin's NPI number?
The NPI number for John Merwin is 1770562209. It was assigned to this individual provider in the NPPES registry on January 12, 2006.
Where is John Merwin located?
John Merwin practices at 10925 Brooktrail Ct, Saint Louis, MO 63141. The listed phone number is (314) 473-6800.
What is John Merwin's specialty?
The primary specialty registered for this NPI is Anesthesiology with taxonomy code 207L00000X.
Is John Merwin enrolled in Medicare?
Yes. John Merwin is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.
Which organizations bill Medicare for John Merwin's services?
According to the CMS Revalidation Reassignment List (October 2026 release), John Merwin reassigns Medicare benefits to 4 organizations: Comprehensive Anesthesia Care PC (Chesterfield, MO), Ssm Health Slu Hospital Anesthesia Physician Billing, LLC (Saint Louis, MO), Ssm Health Care Group (Saint Louis, MO) and Specialists In Anesthesia PC (St Louis, MO). Each reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for John Merwin's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does John Merwin accept?
Health plans from Anthem Blue Cross and Blue Shield and Oscar Insurance Company list John Merwin as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.
Is John Merwin affiliated with any hospitals?
According to CMS data, John Merwin is affiliated with Ssm Health Saint Louis University Hospital.
When was this NPI record last updated?
The NPPES record for John Merwin was last updated on March 5, 2010. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 16 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.
# Dr. John D Merwin, MD · NPI 1770562209
Anesthesiology physician in Saint Louis, Missouri. Individual provider, active in the CMS NPPES registry since January 12, 2006.
## Identity
- **NPI:** 1770562209 (Entity type: Individual)
- **Enumerated:** January 12, 2006
- **Primary specialty:** Anesthesiology · taxonomy 207L00000X
- **State license:** 100344 (Missouri)
- **Sole proprietor:** No
## Practice location
- **Address:** 10925 BROOKTRAIL CT, Saint Louis, MO 63141-8304
- **Phone:** (314) 473-6800 · **Fax:** (314) 473-6800
## Medicare
- **Medicare:** Enrolled (PECOS); accepts Medicare assignment
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health, power mobility devices
- **Bills Medicare through:** 4 organizations under Medicare reassignment (form CMS-855R): Comprehensive Anesthesia Care PC (NPI 1215975156, Chesterfield, MO); Ssm Health Slu Hospital Anesthesia Physician Billing, LLC (NPI 1407232804, Saint Louis, MO); Ssm Health Care Group (NPI 1306589544, Saint Louis, MO); Specialists In Anesthesia PC (NPI 1689619280, St Louis, MO) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** University Of Texas Medical School At San Antonio, class of 1985
## Record status
- **NPPES last updated:** March 5, 2010
- **Other identifiers:** Medicare UPIN E25185 (MO); Medicare PIN 019010681 (MO); Medicaid 203333927 (MO)
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Source: [NPI Profile](https://npiprofile.com/npi/1770562209) · Data from the CMS NPPES public registry.