DR. NATHAN MICHAEL MARKWART D.O.
NPI 1265774574
Internal Medicine - Critical Care Medicine in Boca Raton, FL
About Dr. Nathan Michael Markwart D.o. NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. NATHAN MICHAEL MARKWART D.O. (NPI 1265774574) is an individual critical care medicine provider in Boca Raton, Florida, licensed in Florida (OS 13310) and active in the NPI registry since March 2013. He is enrolled in Medicare PECOS, is affiliated with Bethesda Hospital Inc, and is a graduate of Other (2008).
NPPES Registry Identity
Specialties & Licenses
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. Nathan Michael Markwart D.o. 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 Reassignment
Medicare enrollment records show Nathan Markwart reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.
Boca Raton, FL 33486
- Reassigned Medicare billing, Florida enrollment
- 47 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 6
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 2
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
Bethesda Hospital Inc
Acute Care Hospitals · Boynton Beach, FLBoca Raton Regional Hospital
Acute Care Hospitals · Boca Raton, FLPhysician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 33487 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
Other Providers at the Same Location NPPES 20
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
BOCA RATON, FL 33487
BOCA RATON, FL 33487
BOCA RATON, FL 33487
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 Nathan Markwart's NPI number?
The NPI number for Nathan Markwart is 1265774574. It was assigned to this individual provider in the NPPES registry on March 25, 2013.
Where is Nathan Markwart located?
Nathan Markwart practices at 1601 Clint Moore Rd Suite 100, Boca Raton, FL 33487. The listed phone number is (561) 939-0200.
What is Nathan Markwart's specialty?
The primary specialty registered for this NPI is Internal Medicine, specializing in Critical Care Medicine, with taxonomy code 207RC0200X.
Is Nathan Markwart enrolled in Medicare?
Yes. Nathan Markwart 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 organization bills Medicare for Nathan Markwart's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Nathan Markwart reassigns Medicare benefits to Critical Care Associates Of South Florida LLC (Boca Raton, FL). The 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 Nathan Markwart's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
Is Nathan Markwart affiliated with any hospitals?
According to CMS data, Nathan Markwart is affiliated with Bethesda Hospital Inc and Boca Raton Regional Hospital.
When was this NPI record last updated?
The NPPES record for Nathan Markwart was last updated on September 3, 2015. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 11 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. Nathan Michael Markwart, D.O. · NPI 1265774574
Critical Care Medicine physician in Boca Raton, Florida. Individual provider, active in the CMS NPPES registry since March 25, 2013.
## Identity
- **NPI:** 1265774574 (Entity type: Individual)
- **Enumerated:** March 25, 2013
- **Primary specialty:** Internal Medicine - Critical Care Medicine · taxonomy 207RC0200X
- **State license:** OS 13310 (Florida)
- **Sole proprietor:** No
## Practice location
- **Address:** 1601 CLINT MOORE RD, SUITE 100, Boca Raton, FL 33487-2768
- **Phone:** (561) 939-0200
## 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:** Critical Care Associates Of South Florida LLC (NPI 1619280591, Boca Raton, FL), under Medicare reassignment (form CMS-855R) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Other, class of 2008
## Record status
- **NPPES last updated:** September 3, 2015
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Source: [NPI Profile](https://npiprofile.com/npi/1265774574) · Data from the CMS NPPES public registry.