Robert William Marquis, M.D.
Psychiatry Physician · Mokena, IL
Robert William Marquis, M.D. is a psychiatry physician with a practice address in Mokena, Illinois, and NPI 1376668574, issued on Mar 20, 2007. Check the license (Illinois 0360055192, as entered in NPPES) on the Illinois Department of Financial and Professional Regulation; the Medicare figures below come from public CMS files.
- Name
- Robert William Marquis
- Credential
- M.D.
- Primary taxonomy
- Psychiatry Physician 2084P0800X
- License number
- 0360055192 IL
Self-reported in NPPES; status is on the state search - Practice location
- 19635 LA Grange RD, Mokena, IL 60448
- Phone
- (708) 479-0700
- Enumerated
- Mar 20, 2007
- Record last updated
- Jul 8, 2007 (not updated in 19 years: call before relying on the address or phone)
- Fax
- (708) 479-8959
- Entity
- Type 1 · individual
8 nearest psychiatry physician records → All 2,147 in Illinois → Look up another NPI →
Verify Robert William Marquis 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 0360055192Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
68% fewer Medicare Part D claims than the average psychiatry physician in 2024
317 Medicare Part D claims for 31 beneficiaries, against an average of 1,000 among the 35,054 providers of this specialty who prescribed in Part D.
Most prescribed
- Alprazolam66 claims
- Escitalopram Oxalate29 claims
- Olanzapine25 claims
- Fluoxetine Hcl22 claims
- Mirtazapine19 claims
- Venlafaxine Hcl Er19 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: $3.53
1 payment: food and beverage; the largest payer was Corium, LLC. The 13,693 providers of this specialty with any payment received $4,954.93 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.
Robert William Marquis among 2,147 psychiatry physician records in Illinois
Robert William Marquis, M.D. is one of 2,147 psychiatry physician records with a practice address in Illinois. 69% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2007, is newer than 35% of them.
- NPI issued2007 · 35% of these records are older, 50% newer
- In a Medicare fileYes · 69% of these records are
- In the CMS Doctors and Clinicians fileNo · 41% of these records are
- Record last updated2007 · 53% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 2084P0800X and a Illinois practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Psychiatry Physician providers in Illinois
There are 2,147 psychiatry physician records in Illinois.
All 2,147 in Illinois → Every provider in Mokena → Psychiatry Physician nationwide →
The 8 psychiatry physician records with the nearest ZIP codes
- Elena Tuskenis, M.D.Mokena, IL 604481437481843
- Adnan Arif, M.D.Romeoville, IL 604461710914890
- Mary Cherian, M.D.Morris, IL 604501295781839
- Kala Chinnaswamy, MDRomeoville, IL 604461902482714
- Susan Colegrove, M.D.Romeoville, IL 604461669835997
- James Dyers, D.O.Morris, IL 604501861679888
- Rifki Goldin Mertdogan, M.D.Morris, IL 604501346289980
- Joseph Mullen, D.O.Romeoville, IL 604461972778801
Common questions
What is Robert William Marquis, M.D.'s NPI number?
Robert William Marquis, M.D.'s National Provider Identifier (NPI) is 1376668574, issued on Mar 20, 2007. An NPI identifies a provider in billing; it is not a license.
Where is Robert William Marquis, M.D. located?
The NPPES record lists a practice address at 19635 LA Grange RD, Mokena, IL, 60448. Phone: (708) 479-0700. Providers update this record themselves, so call before visiting.
How can I verify Robert William Marquis, M.D.'s license?
NPPES lists Illinois license number 0360055192, 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 Robert William Marquis, M.D. prescribe under Medicare Part D?
In 2024, Robert William Marquis, M.D. had 317 Medicare Part D claims for 31 beneficiaries; the average among psychiatry physician prescribers was 1,000. 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.