Guy Van Der Werf, MD
NPI 1538154257 · Family Medicine Physician · Estes Park, CO
Enrolled with Medicare as Practitioner - Family Practice · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Guy Van Der Werf, MD is a Family Medicine Physician provider in Estes Park, CO (NPI 1538154257).
Provider details
- NPI number
- 1538154257
- Entity type
- Individual
- Primary specialty
- Family Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- 31317 (CO)
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
20 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
2,014 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 | 453 | $85 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 408 | $68 |
| Insertion of Needle Into Vein for Collection of Blood Sample36415 | 348 | $9 |
| Annual Wellness Visit, Includes a Personalized Prevention Plan of Service (pps), Subsequent VisitG0439 | 228 | $48 |
| Established Patient Office Or Other Outpatient Visit With High Level of Medical Decision Making, If Using Time, 40 Minutes Or More99215 | 92 | $112 |
| Injection of Drug Or Substance Under Skin Or Into Muscle96372 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 112 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Lisinopril | 384 | 106 |
| Levothyroxine Sodium | 325 | 91 |
| Atorvastatin Calcium | 315 | 93 |
| Tamsulosin Hcl | 309 | 99 |
| Prednisone | 253 | 175 |
| Amlodipine Besylate | 247 | 72 |
| Diclofenac Sodium | 192 |
Practice location
Mailing address
Registry dates
- Enumerated
- 2005-09-19
- Last updated
- 2018-09-27
Frequently asked questions
- What is Guy Van Der Werf's NPI number?
- Guy Van Der Werf's National Provider Identifier (NPI) is 1538154257, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Guy Van Der Werf's specialty?
- Guy Van Der Werf is listed in the NPPES registry with a primary specialty of Family Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Guy Van Der Werf located?
- Guy Van Der Werf's practice location on file with NPPES is 131 Stanley Ave Ste 202, Estes Park, CO 80517-6356.
- What is Guy Van Der Werf's phone number?
- The practice phone number listed in the NPPES registry for Guy Van Der Werf is (970) 586-2344.
- Does Guy Van Der Werf accept Medicare?
- Guy Van Der Werf is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Guy Van Der Werf's NPI active?
- Yes — Guy Van Der Werf's NPI (1538154257) is active in the NPPES registry as of the last update on 2018-09-27.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.