Nick J. Karahalios, MD
Internal Medicine Physician · San Clemente, CA
Nick J. Karahalios, MD is an internal medicine physician with a practice address in San Clemente, California, and NPI 1255442505, issued on Aug 31, 2006. Check the license (California G77834, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Nick J. Karahalios
- Credential
- MD
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- G77834 CA
Self-reported in NPPES; status is on the state search - Practice location
- 665 Camino DE Los Mares Ste 309, San Clemente, CA 92673
- Phone
- (949) 487-9034
- Enumerated
- Aug 31, 2006
- Record last updated
- May 27, 2021 (not updated in 5 years: call before relying on the address or phone)
- Fax
- (949) 493-3721
- Medicare enrollment
- Enrolled (PECOS I20090427000558); accepts Medicare assignment
- Medical or professional school
- Un Of California, Irvine, College Of Medicine, 1992
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →
Also registered at 665 Camino DE Los Mares Ste 309
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Steven Cullen, MDInternal Medicine Physician1487765731
Verify Nick J. Karahalios in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license G77834Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
40% fewer Medicare Part D claims than the average internal medicine physician in 2024
1,910 Medicare Part D claims for 108 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 12% of claims. 71 claims were for opioids.
Most prescribed
- Rosuvastatin Calcium78 claims
- Tamsulosin Hcl76 claims
- Zolpidem Tartrate75 claims
- Levothyroxine Sodium72 claims
- Amlodipine Besylate66 claims
- Pantoprazole Sodium64 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.
Industry payments in 2024: $52.95
3 payments; by number, the most common kind was food and beverage; the largest payer was Janssen Pharmaceuticals, Inc. The 50,334 providers of this specialty with any payment received $1,303.06 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
Bills Medicare through one group practice
- San Clemente Internal Medical Group IncSan Clemente, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Nick J. Karahalios among 17,696 internal medicine physician records in California
Nick J. Karahalios, MD is one of 17,696 internal medicine physician records with a practice address in California. 79% 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 5% of them.
- NPI issued2006 · 5% of these records are older, 56% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 63% of these records are
- Graduated1992 · median 2004 among the 11,065 with a school on file
- Record last updated2021 · 61% 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 California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
16 internal medicine physician records list a practice address in San Clemente
They are 16 of the 969 NPPES records with a practice address in San Clemente, and 17,696 internal medicine physician records in California.
All 17,696 in California → Every provider in San Clemente → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Greg Brown, M.D.San Clemente, CA 926731720135346
- Lawrence Chang, M.D.San Clemente, CA 926731528046430
- Steven Cullen, MDSan Clemente, CA 926731487765731
- Karen Garner, MDSan Clemente, CA 926731770639189
- Seema Khan, M.DSan Clemente, CA 926731376795617
- Torsten Kruse, M.D.San Clemente, CA 926731972644482
- Simon Outhwaite, MDSan Clemente, CA 926731851402002
- Faramarz Payandeh, MDSan Clemente, CA 926731346250701
Common questions
What is Nick J. Karahalios, MD's NPI number?
Nick J. Karahalios, MD's National Provider Identifier (NPI) is 1255442505, issued on Aug 31, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Nick J. Karahalios, MD located?
The NPPES record lists a practice address at 665 Camino DE Los Mares Ste 309, San Clemente, CA, 92673. Phone: (949) 487-9034. Providers update this record themselves, so call before visiting.
How can I verify Nick J. Karahalios, MD's license?
NPPES lists California license number G77834, as entered by the provider. Search the Medical Board of California at https://www.mbc.ca.gov/License-Verification/default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Nick J. Karahalios, MD prescribe under Medicare Part D?
In 2024, Nick J. Karahalios, MD had 1,910 Medicare Part D claims for 108 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.