Shelly K. Castles, MD
Family Medicine Physician · Billings, MT
Shelly K. Castles, MD is a family medicine physician with a practice address in Billings, Montana, and NPI 1952410953, issued on Aug 30, 2006. Check the license (Montana 8422, as entered in NPPES) on the Montana Board of Medical Examiners; the Medicare figures below come from public CMS files.
- Name
- Shelly K. Castles
- Credential
- MD
- Primary taxonomy
- Family Medicine Physician 207Q00000X
- License number
- 8422 MT
Self-reported in NPPES; status is on the state search - Practice location
- 2675 Central Ave, Billings, MT 59102
- Phone
- (406) 238-2500
- Enumerated
- Aug 30, 2006
- Record last updated
- Feb 22, 2022
- Medicare enrollment
- Enrolled (PECOS I20100114000136); accepts Medicare assignment
- Medical or professional school
- Texas A & M University System, Hsc, College Of Medicine, 1997
- Entity
- Type 1 · individual
8 nearest family medicine physician records → All 775 in Montana → Look up another NPI →
Also registered at 2675 Central Ave
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify Shelly K. Castles in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMontana Board of Medical Examiners
Search for license 8422Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
34% more Medicare Part D claims than the average family medicine physician in 2024
4,758 Medicare Part D claims for 322 beneficiaries, against an average of 3,544 among the 117,163 providers of this specialty who prescribed in Part D. Brand-name drugs were 12% of claims. 127 claims were for opioids.
Most prescribed
- Levothyroxine Sodium313 claims
- Atorvastatin Calcium185 claims
- Omeprazole160 claims
- Gabapentin150 claims
- Lisinopril150 claims
- Losartan Potassium134 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.
One hospital affiliation
- Billings ClinicBillings, MT · Acute Care Hospitals4 of 5 stars
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through); hospitals matched to CMS Hospital General Information (Care Compare) (data.cms.gov). Star ratings are CMS hospital ratings, not ratings of this provider.
Shelly K. Castles among 775 family medicine physician records in Montana
Shelly K. Castles, MD is one of 775 family medicine physician records with a practice address in Montana. 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 9% of them.
- NPI issued2006 · 9% of these records are older, 50% newer
- In a Medicare fileYes · 75% of these records are
- In the CMS Doctors and Clinicians fileYes · 60% of these records are
- Graduated1997 · median 2007 among the 464 with a school on file
- Record last updated2022 · 53% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207Q00000X and a Montana practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
111 family medicine physician records list a practice address in Billings
They are 111 of the 4,035 NPPES records with a practice address in Billings, and 775 family medicine physician records in Montana.
All 775 in Montana → Every provider in Billings → Family Medicine Physician nationwide →
The 8 family medicine physician records with the nearest ZIP codes
- Jon Bullman, MDBillings, MT 591021255373411
- Heidi Duncan, MDBillings, MT 591021376645341
- Daniel Gall, MDBillings, MT 591021992817951
- Donald Grewell, DOBillings, MT 591021326150285
- Lawrence Hemmer, MDBillings, MT 591021073625463
- Vernon Johnson, MDBillings, MT 591021679568190
- James King, MDBillings, MT 591021174625271
- Frank Michels, MDBillings, MT 591021215971155
Common questions
What is Shelly K. Castles, MD's NPI number?
Shelly K. Castles, MD's National Provider Identifier (NPI) is 1952410953, issued on Aug 30, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Shelly K. Castles, MD located?
The NPPES record lists a practice address at 2675 Central Ave, Billings, MT, 59102. Phone: (406) 238-2500. Providers update this record themselves, so call before visiting.
How can I verify Shelly K. Castles, MD's license?
NPPES lists Montana license number 8422, as entered by the provider. Search the Montana Board of Medical Examiners at https://ebiz.mt.gov/POL/. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Shelly K. Castles, MD prescribe under Medicare Part D?
In 2024, Shelly K. Castles, MD had 4,758 Medicare Part D claims for 322 beneficiaries; the average among family medicine physician prescribers was 3,544. 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.