Mark W. Sij, D.O.
Internal Medicine Physician · Kaufman, TX
Mark W. Sij, D.O. is an internal medicine physician with a practice address in Kaufman, Texas, and NPI 1396705919, issued on Mar 27, 2006. Check the license (Texas K9421, as entered in NPPES) on the Texas Medical Board; the Medicare figures below come from public CMS files.
- Name
- Mark W. Sij
- Credential
- D.O.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- K9421 TX
Self-reported in NPPES; status is on the state search - Practice location
- 874 ED Hall Dr Ste B-108, Kaufman, TX 75142
- Phone
- (972) 932-5555
- Enumerated
- Mar 27, 2006
- Record last updated
- Aug 5, 2011 (not updated in 15 years: call before relying on the address or phone)
- Fax
- (972) 932-5557
- Medicaid ID
- 045766504 TX
- Medicare enrollment
- Enrolled (PECOS I20090325000516); accepts Medicare assignment
- Medical or professional school
- University Of North Texas Hsc, College Of Osteopathic Med, 1998
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
Also registered at 874 ED Hall Dr Ste B-108
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Jill Glick, D.O.Family Medicine Physician1851351589
- Sara Zaleta, M.D.Internal Medicine Physician1336106913
Verify Mark W. Sij in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersTexas Medical Board
Search for license K9421Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
7.6 times the Medicare Part D claims of the average internal medicine physician in 2024
24,152 Medicare Part D claims for 1,270 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. 1,608 claims were for opioids.
Most prescribed
- Hydrocodone-Acetaminophen801 claims
- Atorvastatin Calcium751 claims
- Pantoprazole Sodium684 claims
- Levothyroxine Sodium670 claims
- Gabapentin641 claims
- Amlodipine Besylate558 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: $2,065.39
118 payments; by number, the most common kind was food and beverage; the largest payer was AstraZeneca Pharmaceuticals LP. 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
- Texas Health Physicians GroupKaufman, TX
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
9 internal medicine physician records list a practice address in Kaufman
They are 9 of the 154 NPPES records with a practice address in Kaufman, and 9,175 internal medicine physician records in Texas.
All 9 in Kaufman → All 9,175 in Texas → Every provider in Kaufman →
Other internal medicine physician records in Texas
- Muhammad A. Sattar, MDDallas, TX1760465553
- Gayatri Aaluri, MDGalveston, TX1821928508
- Anunaya AashishDenton, TX1134246374
- Queenie Ann Abad, M.D.San Antonio, TX1174979785
- Fuad Abaleka, M.DLubbock, TX1861925596
- Carol Abalihi, M.D.El Paso, TX1326136243
- Oliverio Abarca Guzman, MDHarlingen, TX1346972940
- Obinna Abaribe, M.DMansfield, TX1457704355
- Enyinnaya Abarikwu, MDTyler, TX1174788178
- Sulaiman Abawi, D.O.Frisco, TX1780845255
Common questions
What is Mark W. Sij, D.O.'s NPI number?
Mark W. Sij, D.O.'s National Provider Identifier (NPI) is 1396705919, issued on Mar 27, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Mark W. Sij, D.O. located?
The NPPES record lists a practice address at 874 ED Hall Dr Ste B-108, Kaufman, TX, 75142. Phone: (972) 932-5555. Providers update this record themselves, so call before visiting.
How can I verify Mark W. Sij, D.O.'s license?
NPPES lists Texas license number K9421, as entered by the provider. Search the Texas Medical Board at https://profile.tmb.state.tx.us/Search.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Mark W. Sij, D.O. prescribe under Medicare Part D?
In 2024, Mark W. Sij, D.O. had 24,152 Medicare Part D claims for 1,270 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.