Mark Stephen Walmer, MD
Internal Medicine Physician · Chandler, AZ
Mark Stephen Walmer, MD is an internal medicine physician with a practice address in Chandler, Arizona, and NPI 1629166053, issued on Oct 11, 2006. Check the license (Arizona 15974, as entered in NPPES) on the Arizona Medical Board; the Medicare figures below come from public CMS files.
- Name
- Mark Stephen Walmer
- Credential
- MD
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- 15974 AZ
Self-reported in NPPES; status is on the state search - Practice location
- 655 S Dobson RD, Chandler, AZ 85224
- Phone
- (480) 821-3821
- Enumerated
- Oct 11, 2006
- Record last updated
- Sep 16, 2011 (not updated in 15 years: call before relying on the address or phone)
- Fax
- (186) 677-7239
- Medicaid ID
- 274639 AZ
- Medicare enrollment
- Enrolled (PECOS I20101020000282); accepts Medicare assignment
- Medical or professional school
- Medical University Of South Carolina College Of Medicine, 1984
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 2,853 in Arizona → Look up another NPI →
Also registered at 655 S Dobson RD
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Miriam Arce, M.D.Internal Medicine Physician1417004433
- Patricia AultPhysical Therapist1124404157
- Mara Baier, D.O.Family Medicine Physician1407811797
- Sandra Bebak, MDFamily Medicine Physician1437113636
Verify Mark Stephen Walmer in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersArizona Medical Board
Search for license 15974Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
3.7 times the Medicare Part D claims of the average internal medicine physician in 2024
11,903 Medicare Part D claims for 978 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 10% of claims. 284 claims were for opioids.
Most prescribed
- Atorvastatin Calcium760 claims
- Levothyroxine Sodium574 claims
- Lisinopril426 claims
- Pantoprazole Sodium383 claims
- Metformin Hcl339 claims
- Simvastatin271 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
Bills Medicare through one group practice
- East Valley Internal Medicine PCChandler, AZ
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Mark Stephen Walmer among 2,853 internal medicine physician records in Arizona
Mark Stephen Walmer, MD is one of 2,853 internal medicine physician records with a practice address in Arizona. 75% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2006, is newer than 13% of them.
- NPI issued2006 · 13% of these records are older, 55% newer
- In a Medicare fileYes · 75% of these records are
- In the CMS Doctors and Clinicians fileYes · 58% of these records are
- Graduated1984 · median 2003 among the 1,643 with a school on file
- Record last updated2011 · 51% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207R00000X and a Arizona practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
93 internal medicine physician records list a practice address in Chandler
They are 93 of the 5,497 NPPES records with a practice address in Chandler, and 2,853 internal medicine physician records in Arizona.
All 2,853 in Arizona → Every provider in Chandler → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Ammar Alsheikh, M.D.Chandler, AZ 852241083609515
- Rudolph Cane, MDChandler, AZ 852241700865144
- Susan Carter, M.D.Chandler, AZ 852241922060433
- Melanie Cloonan Schulte, MDChandler, AZ 852241376521914
- Ralph D'Silva, M.D.Chandler, AZ 852241871594259
- Ravi Gupta, MDChandler, AZ 852241790751949
- Amita Gupta, MDChandler, AZ 852241962462630
- James Lieber, MDChandler, AZ 852241083690283
Common questions
What is Mark Stephen Walmer, MD's NPI number?
Mark Stephen Walmer, MD's National Provider Identifier (NPI) is 1629166053, issued on Oct 11, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Mark Stephen Walmer, MD located?
The NPPES record lists a practice address at 655 S Dobson RD, Chandler, AZ, 85224. Phone: (480) 821-3821. Providers update this record themselves, so call before visiting.
How can I verify Mark Stephen Walmer, MD's license?
NPPES lists Arizona license number 15974, as entered by the provider. Search the Arizona Medical Board at https://www.azmd.gov/. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Mark Stephen Walmer, MD prescribe under Medicare Part D?
In 2024, Mark Stephen Walmer, MD had 11,903 Medicare Part D claims for 978 beneficiaries; the average among internal medicine physician prescribers was 3,176. Part D covers Medicare prescriptions only.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.