Dr. Nick J. Karahalios, MD
- Medicare services, 2024
- 1,427
- Medicare patients, 2024
- 104
- Part D claims, 2024
- 1,910
- MIPS score, 2024
- 90
- Hospital affiliations
- 2
- Practice address
- 665 Camino De Los Mares, San Clemente, CA 92673
- Practice phone
- Call (949) 951-2020
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
South Orange County Outpatient Surgical Center Inc
San Clemente, California
Find Dr. Karahalios' professional email, personal email and mobile number
Dmand AI checks each channel through healthcare-specific waterfall enrichment. See what is on file with a free account, with practice phones, licenses and affiliations.
Dr. Nick J. Karahalios is an internist in San Clemente, California
Dr. Karahalios practices at South Orange County Outpatient Surgical Center Inc in San Clemente, California.
Dr. Karahalios' NPI, 1255442505, was assigned on August 31, 2006. Dr. Karahalios graduated from Keck School of Medicine of USC in 1992. Dr. Karahalios' California license number on file is G77834.
- NPI
- 1255442505NPI Registry (opens in a new tab)
- Medicare PAC ID
- 1759313299
- NPI enumeration date
- August 31, 2006
- NPI status
- Active
- Accepts Medicare assignment
- Yes
- Offers telehealth
- Yes
- Practice phone
- (949) 951-2020
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 60
- Medical school graduation
- 1992
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Practice Data; and Doctors and Clinicians National Downloadable File (CMS)
Dr. Nick J. Karahalios practices at South Orange County Outpatient Surgical Center Inc in San Clemente, California
Dr. Karahalios' primary practice is South Orange County Outpatient Surgical Center Inc, at 665 Camino De Los Mares, San Clemente, CA 92673 in Orange County. The practice phone is (949) 951-2020.
- South Orange County Outpatient Surgical Center Inc665 Camino De Los Mares, San Clemente, CA 92673 · Orange CountyPhone(949) 951-2020
Sources: NPPES NPI Registry (CMS); and Dmand AI Practice Data
Dr. Nick J. Karahalios is affiliated with 7 sites of care and 1 medical group
Dr. Karahalios' primary practice is South Orange County Outpatient Surgical Center Inc in San Clemente, California. Dr. Karahalios is also affiliated with Providence Mission Hospital. The medical group on file is San Clemente Internal Medical Group. Dmand AI also links Dr. Karahalios to 1 more hospital, 1 group practice or clinic, 1 home health agency, 1 hospice and 1 skilled nursing facility, each named with a free account.
Sources: NPPES NPI Registry (CMS); Dmand AI Practice Data; and Dmand AI Affiliation Data
Dmand AI tracks the EHR system at Dr. Nick J. Karahalios' practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Karahalios practices, 6 sites in all. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| South Orange County Outpatient Surgical Center Inc | Available with a free account |
| +6 more affiliated sites | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. Nick J. Karahalios is one of 16,751 internists in California
Internal medicine is Dr. Karahalios' primary specialty in the NPI Registry, under taxonomy code 207R00000X. Dr. Karahalios is board certified in internal medicine by the American Board of Internal Medicine. Dr. Karahalios has a license on file in California.
Specialties and state licenses
- Internal medicine, CaliforniaPrimary
Clinical focus
Dmand AI lists acid reflux, acute kidney failure, acute mini-stroke (TIA), acute sinusitis, acute skin infection, aneurysm, arteritis and arthritis among the conditions Dr. Karahalios treats.
Internists near Dr. Karahalios
Counts of internists with a Dmand AI profile, by place and practice. Each opens the list.
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Peer Benchmarks
Dr. Nick J. Karahalios billed Medicare for 1,427 services in 2024
CMS data shows 1,427 Medicare services from Dr. Karahalios across 15 procedure codes in 2024, for 104 Medicare patients. Medicare paid $96,659 for them.
Dr. Karahalios' Medicare services by type, 2023 to 2024
- 2023
- 2024
- Office and hospital visits
- 2023: 8942024: 8416%
- Surgery
- 2023: 4502024: 4158%
- Tests and treatments
- 2023: 1122024: 9515%
- Other services
- 2023: 642024: 589%
- Lab and pathology
- 2023: 172024: 186%
Where Dr. Karahalios' Medicare services took place, 2024
- In an office1,37096%
- In a facility574%
Dr. Karahalios compared with the California median for internists, 2024
- Dr. Karahalios
- California median
- Medicare services
- 1,427vs 3614.0 times
- Medicare patients
- 104vs 15131% below
- Part D claims
- 1,418vs 4213.4 times
Medians across 15,815 internists in California with Dmand AI profiles that report each measure.
Dr. Karahalios' most billed Medicare procedure codes, 2024
CMS publishes codes billed for 11 or more Medicare patients. Each label is the code family; CPT descriptions are licensed by the AMA.
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Medicare shows one payer. Book a meeting to get commercial claims data for Dr. Karahalios and other internists in California.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. Nick J. Karahalios treated 104 Medicare patients in 2024, average age 79
CMS counts 104 Medicare patients who saw Dr. Karahalios in 2024. The largest group is 75 to 84, with 40 patients. 75% of them have high blood pressure, and 75% have high cholesterol. Their average risk score is 1.19, where 1.00 is the Medicare average.
Across all payers, Dmand AI patient panel data puts Dr. Karahalios' median patient age at 73, with 50% women.
Dr. Karahalios' Medicare patients by age, 2024
Dr. Karahalios' Medicare patients by sex, 2024
- Women5250%
- Men5250%
Chronic conditions among Dr. Karahalios' Medicare patients, 2024
- High blood pressure75%
- High cholesterol75%
- Arthritis54%
- Ischemic heart disease38%
- Atrial fibrillation30%
- Cancer24%
- Chronic kidney disease23%
- Osteoporosis22%
Share of Medicare patients with each condition. A patient can have several.
Dr. Karahalios' patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 73
Patient panel by sex, all payers
- Women50%
- Men50%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
Dr. Nick J. Karahalios wrote 1,910 Medicare Part D claims in 2024
In 2024, Dr. Karahalios wrote 1,910 Medicare Part D claims for 108 patients. 88% of them were for generic drugs. CMS names the drug for 1,418 of them, across 52 drugs with 11 or more claims each, at $116,267 in total drug cost. In 2023, CMS named 1,325 claims across 48 drugs.
Dr. Karahalios' Part D claims by kind of drug, 2024
- Generic1,672 claims88%
- Brand-name238 claims12%
Dr. Karahalios' most prescribed drugs by claims, 2024
CMS names a drug when it has 11 or more claims. Share is of the claims for drugs CMS names.
Drug classes CMS tracks in Dr. Karahalios' Part D claims, 2024
- Opioids4%71 of 1,910 claims
- Antibiotics8%161 of 1,910 claims
Share of all Part D claims for each drug class CMS reports on. Classes with no claims are left out.
Part D claims for drugs CMS names, 2023 to 2024
- 2023
- 2024
- Claims for drugs CMS names
- 2023: 1,3252024: 1,4187%
Drugs named by CMS: 52 in 2024, 48 in 2023.
Sources: Medicare Part D Prescribers - by Provider and Drug (CMS), 2024 data, released May 6, 2026; and Medicare Part D Prescribers - by Provider (CMS), 2024 data
Dr. Nick J. Karahalios scored 90 out of 100 in Medicare's MIPS program for 2024
CMS publishes a Merit-based Incentive Payment System (MIPS) score of 90 out of 100 for Dr. Karahalios for performance year 2024, reported as part of a group. Dr. Karahalios accepts Medicare assignment, so Medicare's approved amount is taken as full payment. CMS lists Dr. Karahalios as offering telehealth. CMS counts 96 procedures of removal of skin lesions by Dr. Karahalios, more than 75% of the clinicians it reports for that procedure.
- Accepts Medicare assignment
- Yes
- Offers telehealth
- Yes
Dr. Karahalios' MIPS scores, performance year 2024
- 90of 100Final score
- 98.1of 100Quality
- 40of 100Improvement Activities
- 71of 100Cost
Each score is out of 100. The final score weighs the categories CMS scored for this clinician.
Where Dr. Karahalios ranks in Medicare procedure volume
- Removal of skin lesions
- 75th percentile96 procedures
CMS ranks each clinician against every clinician it reports for the same procedure category.
Melanoma (skin cancer) excision: 1 to 10 procedures (CMS shows small counts as a range)
Sources: Doctors and Clinicians National Downloadable File (CMS); Clinician Public Reporting: Overall MIPS Performance (CMS), 2024 data, released September 10, 2026; and Doctors and Clinicians Utilization Data (CMS)
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Dr. Nick J. Karahalios received $787 in industry payments from 2016 to 2025
CMS Open Payments shows 29 general payments to Dr. Karahalios from 13 drug and device companies from 2016 to 2025. Food and beverage make up the largest share, 97% of the total. Janssen Pharmaceuticals, Inc paid the most, $156.
General payments to Dr. Karahalios by program year, 2016 to 2025
General payments to Dr. Karahalios by kind, 2016 to 2025
- Food and beverage$76697%
- Education$213%
Companies that paid Dr. Karahalios the most, 2016 to 2025
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Dr. Nick J. Karahalios graduated from Keck School of Medicine of USC
Dr. Karahalios graduated from Keck School of Medicine of USC in 1992.
- Medical school
- Board certified in internal medicine
Source: Dmand AI Professional Profile Data
Dr. Nick J. Karahalios accepts plans from 1 insurance carrier
Dr. Karahalios is in network with 1 carrier, including CMS Medicare. Medicare plans come from the most carriers, 1. Check the plan with the practice before a visit.
- CMS Medicare
Source: Dmand AI Insurance Network Data
Sources for Dr. Nick J. Karahalios's profile data
| Data on this page | Source |
|---|---|
| NPI, name, sex, specialty and licenses | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Professional Profile Data |
| Practice locations and phone | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Practice Data |
| Primary practice, affiliations and health system | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Practice DataDmand AI Affiliation Data |
| Medicare services and procedure codes | Medicare Physician & Other Practitioners - by Provider and Service (CMS) (opens in a new tab) |
| State medians for the same specialty | Dmand AI Peer Benchmarks |
| Medicare patients and the all-payer patient panel | Dmand AI Patient Panel DataMedicare Physician & Other Practitioners - by Provider (CMS) (opens in a new tab) |
| Part D prescribing | Medicare Part D Prescribers - by Provider and Drug (CMS) (opens in a new tab)Medicare Part D Prescribers - by Provider (CMS) (opens in a new tab) |
| MIPS scores, telehealth, assignment and procedure percentiles | Doctors and Clinicians National Downloadable File (CMS) (opens in a new tab)Clinician Public Reporting: Overall MIPS Performance (CMS) (opens in a new tab)Doctors and Clinicians Utilization Data (CMS) (opens in a new tab) |
| Industry payments | Open Payments (CMS) (opens in a new tab) |
| Training, board certification and memberships | Dmand AI Professional Profile Data |
| Insurance carriers and plan types | Dmand AI Insurance Network Data |
| EHR at each practice site | Dmand AI Technology Install Data |
| Similar physicians | Dmand AI Affiliation Data |
Data last refreshed October 2026Report an inaccuracyRemove my information
FAQ
Frequently asked questions about Dr. Nick J. Karahalios
Spotted something out of date? Email hello@dmand.ai and we will check the record. Contact details live in the free trial.
What is Dr. Nick J. Karahalios' NPI number?
Dr. Nick J. Karahalios' NPI number is 1255442505. It was assigned on August 31, 2006, and it is active in the NPI Registry.
What kind of doctor is Dr. Nick J. Karahalios?
Dr. Nick J. Karahalios is an internist in San Clemente, California. The primary specialty in the NPI Registry is Internal Medicine Physician (taxonomy code 207R00000X).
Where does Dr. Nick J. Karahalios practice?
Dr. Karahalios practices at 665 Camino De Los Mares, San Clemente, CA 92673. Dr. Karahalios' primary practice is South Orange County Outpatient Surgical Center Inc in San Clemente, California. Dmand AI also links Dr. Karahalios to 1 hospital, 1 group practice or clinic, 1 home health agency, 1 hospice and 1 skilled nursing facility.
What is Dr. Nick J. Karahalios' office phone number?
The practice phone on file for Dr. Karahalios is (949) 951-2020.
What is Dr. Nick J. Karahalios' medical license number?
Dr. Karahalios' California license number on file is G77834.
Which hospitals is Dr. Nick J. Karahalios affiliated with?
Dr. Karahalios is affiliated with Providence Mission Hospital. Dmand AI links Dr. Karahalios to 1 more hospital.
What medical group is Dr. Nick J. Karahalios part of?
Dr. Karahalios is linked to San Clemente Internal Medical Group.
Does Dr. Nick J. Karahalios accept Medicare?
Yes. CMS data shows Dr. Karahalios billed Medicare for 1,427 services in 2024, and Dr. Karahalios accepts Medicare assignment.
Does Dr. Nick J. Karahalios offer telehealth?
Yes. The CMS Doctors and Clinicians file lists Dr. Karahalios as offering telehealth services.
What is Dr. Nick J. Karahalios' MIPS score?
Dr. Karahalios' MIPS final score for performance year 2024 is 90 out of 100, reported as part of a group.
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How many Medicare patients does Dr. Nick J. Karahalios see?
CMS counts 104 Medicare patients who saw Dr. Karahalios in 2024, with an average age of 79.
Is Dr. Nick J. Karahalios board certified?
Yes. Dr. Karahalios is board certified in internal medicine by the American Board of Internal Medicine.
What services does Dr. Nick J. Karahalios bill to Medicare?
In 2024, Dr. Karahalios' most billed Medicare services were office visit, established patient (99214), surgery: heart and blood vessels (36415) and surgery: skin and soft tissue (17000).
Where did Dr. Nick J. Karahalios go to medical school?
Dr. Karahalios graduated from Keck School of Medicine of USC in 1992.
What drugs does Dr. Nick J. Karahalios prescribe most?
In 2024 Medicare Part D data, Dr. Karahalios' most prescribed drugs by claims were Rosuvastatin Calcium, Tamsulosin HCl and Zolpidem Tartrate.
Has Dr. Nick J. Karahalios received payments from drug or device companies?
CMS Open Payments shows $787 in general payments to Dr. Karahalios from 13 companies from 2016 to 2025. The largest total came from Janssen Pharmaceuticals, Inc.
How long has Dr. Nick J. Karahalios been practicing?
Dr. Karahalios graduated from medical school in 1992, 34 years ago.
What insurance does Dr. Nick J. Karahalios accept?
Dr. Karahalios is in network with 1 carrier, including CMS Medicare. Medicare plans come from the most carriers, 1. Check the plan with the practice before a visit.
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