Patricia Katherine Merlo, D.O.
Internal Medicine Physician · Elgin, IL
Patricia Katherine Merlo, D.O. is an internal medicine physician with a practice address in Elgin, Illinois, and NPI 1972501161, issued on Jul 12, 2005. Check the license (Illinois 036089508, as entered in NPPES) on the Illinois Department of Financial and Professional Regulation; the Medicare figures below come from public CMS files.
- Name
- Patricia Katherine Merlo
- Credential
- D.O.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- 036089508 IL
Self-reported in NPPES; status is on the state search - Practice location
- 1710 N Randall RD, Elgin, IL 60123
- Phone
- (847) 214-5755
- Enumerated
- Jul 12, 2005
- Record last updated
- Apr 19, 2022
- Fax
- (847) 214-9606
- Medicaid ID
- 036089508 IL
- Medicare enrollment
- Enrolled (PECOS I20040423000630); accepts Medicare assignment
- Medical or professional school
- Perelman School Of Med At The University Of Pennsylvania, 1990
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 7,238 in Illinois → Look up another NPI →
Also registered at 1710 N Randall RD
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify Patricia Katherine Merlo in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersIllinois Department of Financial and Professional Regulation
Search for license 036089508Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
2.1 times the Medicare Part D claims of the average internal medicine physician in 2024
6,810 Medicare Part D claims for 581 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 10% of claims. 33 claims were for opioids.
Most prescribed
- Atorvastatin Calcium620 claims
- Levothyroxine Sodium437 claims
- Amlodipine Besylate369 claims
- Lisinopril308 claims
- Metoprolol Succinate282 claims
- Losartan Potassium261 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.
Bills Medicare through one group practice
- Advocate Health And Hospitals CorporationElgin, IL
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Patricia Katherine Merlo among 7,238 internal medicine physician records in Illinois
Patricia Katherine Merlo, D.O. is one of 7,238 internal medicine physician records with a practice address in Illinois. 73% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2005, is newer than 0% of them.
- NPI issued2005 · 0% of these records are older, 93% newer
- In a Medicare fileYes · 73% of these records are
- In the CMS Doctors and Clinicians fileYes · 50% of these records are
- Graduated1990 · median 2003 among the 3,580 with a school on file
- Record last updated2022 · 47% 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 Illinois practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
62 internal medicine physician records list a practice address in Elgin
They are 62 of the 2,268 NPPES records with a practice address in Elgin, and 7,238 internal medicine physician records in Illinois.
All 7,238 in Illinois → Every provider in Elgin → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Richard Baley, M.D.Elgin, IL 601231184693327
- Jawed Ehsan, MDElgin, IL 601231114901501
- John Fiedler, M.D.Elgin, IL 601231487623716
- Dennis Flynn, M.D.Elgin, IL 601231295704435
- Jeffrey Garb, M.D.Elgin, IL 601231023063237
- Anandita Gephart, M.D.Elgin, IL 601231790709343
- Michael Hernandez, M.D.Elgin, IL 601231972501096
- Ronald Hirsch, M.D.Elgin, IL 601231467450585
Common questions
What is Patricia Katherine Merlo, D.O.'s NPI number?
Patricia Katherine Merlo, D.O.'s National Provider Identifier (NPI) is 1972501161, issued on Jul 12, 2005. An NPI identifies a provider in billing; it is not a license.
Where is Patricia Katherine Merlo, D.O. located?
The NPPES record lists a practice address at 1710 N Randall RD, Elgin, IL, 60123. Phone: (847) 214-5755. Providers update this record themselves, so call before visiting.
How can I verify Patricia Katherine Merlo, D.O.'s license?
NPPES lists Illinois license number 036089508, as entered by the provider. Search the Illinois Department of Financial and Professional Regulation at https://idfpr.illinois.gov/checklicense.html. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Patricia Katherine Merlo, D.O. prescribe under Medicare Part D?
In 2024, Patricia Katherine Merlo, D.O. had 6,810 Medicare Part D claims for 581 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.