Nick Karahalios, MD
NPI 1255442505 · Internal Medicine Physician · San Clemente, CA
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Nick Karahalios, MD is a Internal Medicine Physician provider in San Clemente, CA (NPI 1255442505).
Provider details
- NPI number
- 1255442505
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- G77834 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
19 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
1,369 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
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 .
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 | 595 | $138 |
| Insertion of Needle Into Vein for Collection of Blood Sample36415 | 272 | $9 |
| Destruction of Precancer Skin Growth, 1 Growth17000 | 93 | $75 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 85 | $98 |
| Office Or Other Outpatient Visit for the Evaluation and Management of Established Patient That May Not Require Presence of Healthcare Professional99211 | 62 | $26 |
| Administration of Influenza Virus VaccineG0008 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 52 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Rosuvastatin Calcium | 78 | 21 |
| Tamsulosin Hcl | 76 | 16 |
| Zolpidem Tartrate | 75 | 15 |
| Levothyroxine Sodium | 72 | 18 |
| Amlodipine Besylate | 66 | 18 |
| Pantoprazole Sodium | 64 | 22 |
| Azithromycin |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$53 across 3 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-08-31
- Last updated
- 2021-05-27
- Certified
- 2021-05-27
Frequently asked questions
- What is Nick Karahalios's NPI number?
- Nick Karahalios's National Provider Identifier (NPI) is 1255442505, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Nick Karahalios's specialty?
- Nick Karahalios is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Nick Karahalios located?
- Nick Karahalios's practice location on file with NPPES is 665 Camino De Los Mares Ste 309, San Clemente, CA 92673-2841.
- What is Nick Karahalios's phone number?
- The practice phone number listed in the NPPES registry for Nick Karahalios is (949) 487-9034.
- Does Nick Karahalios accept Medicare?
- Nick Karahalios is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Nick Karahalios's NPI active?
- Yes — Nick Karahalios's NPI (1255442505) is active in the NPPES registry as of the last update on 2021-05-27.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.