Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.
NPIDirectory

Dr. Robert Nathan Long, MD

Individual provider Internal Medicine Physician · NPI 1639300262

Dr. Robert Nathan Long, MD practises Internal Medicine in Saint Louis, Missouri. Graduated from Indiana University School of Medicine in 2012, 14 years ago. Practices with Mercy Clinic Adult Hospitalists - St Louis, LLC, a 141-clinician group and accepts Medicare assignment. Licensed in Missouri.

Years since qualifying
14
Trained at
Indiana University School of Medicine
Licensed in
MO
In the registry since
2009
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

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Practice location Address checks out

621 S New Ballas Rd Ste 3016B
Saint Louis, MO 63141-8232 Not confirmed with CMS for 13 years — call before visiting
Phone: (314) 251-6339
Fax: (314) 251-4564
Show map & directions

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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Internal Medicine Physician (primary) Taxonomy 207R00000X · Licence 2012017791 (MO)

Record details

NPI number1639300262
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedJuly 30, 2009
Last updated in NPPESDecember 21, 2012

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyINTERNAL MEDICINE
Also practisesHOSPITALIST
Medical schoolINDIANA UNIVERSITY SCHOOL OF MEDICINE
Graduated 2012 (14 years in practice)
Group practice Mercy Clinic Adult Hospitalists - St. Louis, Llc — 141 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
Practice locations2 on file with Medicare

Procedures

From CMS Care Compare, which counts the procedures a clinician billed to Original Medicare and Medicare Advantage over a recent 12-month period. CMS reports a fixed list of common procedures, so this is not everything the clinician does. Counts of 10 or fewer are given as a range, because CMS withholds small numbers.

Skin biopsy 1–10 times

The percentile compares how often this clinician performed the procedure with other clinicians who performed it, as CMS calculates it. It measures volume, not outcomes or skill.

Medicare patients and services, 2024

From the CMS Medicare Physician & Other Practitioners file for calendar year 2024. It counts Original Medicare patients only, so a practice that mostly sees Medicare Advantage or privately insured patients looks smaller here than it is.

Medicare patients238
Services billed 613 a service is one billed item, such as a visit, a test or a procedure
Average patient age76

Dollar amounts are not shown. What Medicare pays a practice is gross billings, before staff, premises and tax and including the cost of any drugs it administers, so it is not what a clinician earns.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician.

  • Mercy Hospital St Louis Hospital · Saint Louis, MO · listed as Mercy Hospitals East Communities Mercy Hospital St Louis

Colleagues at Mercy Clinic Adult Hospitalists - St Louis, LLC

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 141 clinicians in the practice; 12 are shown here.

Other providers in Saint Louis