Shelly Castles, MD
NPI 1952410953 · Family Medicine Physician · Billings, MT
Enrolled with Medicare as Practitioner - Family Practice · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Shelly Castles, MD is a Family Medicine Physician provider in Billings, MT (NPI 1952410953).
Provider details
- NPI number
- 1952410953
- Entity type
- Individual
- Primary specialty
- Family Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Female
- Sole proprietor
- No
- License
- 8422 (MT)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
19 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)28% of score
612 Medicare services, 2024 (ranked within specialty)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 173 | $82 |
| Visit Complexity Inherent to Evaluation and Management Associated With Medical Care Services That Serve As the Continuing Focal Point for All Needed Health Care Services And/Or With Medical Care Services That Are Part of Ongoing Care Related to a Patient'SG2211 | 156 | $16 |
| Established Patient Office Or Other Outpatient Visit With High Level of Medical Decision Making, If Using Time, 40 Minutes Or More99215 | 120 | $101 |
| Annual Wellness Visit, Includes a Personalized Prevention Plan of Service (pps), Subsequent VisitG0439 | 42 | $14 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 37 | $64 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 87 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Levothyroxine Sodium | 313 | 63 |
| Atorvastatin Calcium | 185 | 46 |
| Omeprazole | 160 | 45 |
| Gabapentin | 150 | 32 |
| Lisinopril | 150 | 35 |
| Losartan Potassium | 134 | 38 |
| Simvastatin | 132 |
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-08-30
- Last updated
- 2022-02-22
- Certified
- 2022-02-22
Frequently asked questions
- What is Shelly Castles's NPI number?
- Shelly Castles's National Provider Identifier (NPI) is 1952410953, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Shelly Castles's specialty?
- Shelly Castles is listed in the NPPES registry with a primary specialty of Family Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Shelly Castles located?
- Shelly Castles's practice location on file with NPPES is 2675 Central Ave, Billings, MT 59102-6686.
- What is Shelly Castles's phone number?
- The practice phone number listed in the NPPES registry for Shelly Castles is (406) 238-2500.
- Does Shelly Castles accept Medicare?
- Shelly Castles is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Shelly Castles's NPI active?
- Yes — Shelly Castles's NPI (1952410953) is active in the NPPES registry as of the last update on 2022-02-22.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.