Karen J. Mass, MD
Obstetrics & Gynecology Physician · Lake Forest, IL
Karen J. Mass, MD is an obstetrics & gynecology physician with a practice address in Lake Forest, Illinois, and NPI 1710179759, issued on Aug 14, 2007. Check the license (Illinois 036-093084, as entered in NPPES) on the Illinois Department of Financial and Professional Regulation; the Medicare figures below come from public CMS files.
- Name
- Karen J. Mass
- Credential
- MD
- Primary taxonomy
- Obstetrics & Gynecology Physician 207V00000X
- License number
- 036-093084 IL
Self-reported in NPPES; status is on the state search - Practice location
- 840 S Waukegan RD Ste 208, Lake Forest, IL 60045
- Phone
- (847) 295-0433
- Enumerated
- Aug 14, 2007
- Record last updated
- Mar 7, 2024
- Fax
- (847) 234-0034
- Medicare enrollment
- Enrolled (PECOS I20050824000196); accepts Medicare assignment
- Medical or professional school
- University Of Illinois College Of Med (Chi/Peor/Rock/Chm-Urb), 1988
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest obstetrics & gynecology physician records → All 2,062 in Illinois → Look up another NPI →
Also registered at 840 S Waukegan RD Ste 208
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Leslie Rubeck, APRN, CNMAdvanced Practice Midwife1952688459
Verify Karen J. Mass 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 036-093084Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
3.6 times the Medicare Part D claims of the average obstetrics & gynecology physician in 2024
592 Medicare Part D claims for 189 beneficiaries, against an average of 165 among the 28,733 providers of this specialty who prescribed in Part D. Brand-name drugs were 7% of claims.
Most prescribed
- Estradiol109 claims
- Valacyclovir75 claims
- Alendronate Sodium70 claims
- Raloxifene Hcl66 claims
- Clotrimazole-Betamethasone36 claims
- Clobetasol Propionate17 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: $122.94
7 payments; by number, the most common kind was food and beverage; the largest payer was Merck Sharp & Dohme LLC. The 21,429 providers of this specialty with any payment received $1,030.61 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.
Karen J. Mass among 2,062 obstetrics & gynecology physician records in Illinois
Karen J. Mass, MD is one of 2,062 obstetrics & gynecology physician records with a practice address in Illinois. 72% 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 46% of them.
- NPI issued2007 · 46% of these records are older, 47% newer
- In a Medicare fileYes · 72% of these records are
- In the CMS Doctors and Clinicians fileYes · 57% of these records are
- Graduated1988 · median 2006 among the 1,168 with a school on file
- Record last updated2024 · 51% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207V00000X and a Illinois practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
18 obstetrics & gynecology physician records list a practice address in Lake Forest
They are 18 of the 821 NPPES records with a practice address in Lake Forest, and 2,062 obstetrics & gynecology physician records in Illinois.
All 2,062 in Illinois → Every provider in Lake Forest → Obstetrics & Gynecology Physician nationwide →
The 8 obstetrics & gynecology physician records with the nearest ZIP codes
- Tanner Colegrove, M.D.Lake Forest, IL 600451003941113
- Robert Hartman, M.D.Lake Forest, IL 600451346336310
- Heather Heiberger, M.D.Lake Forest, IL 600451053330720
- Jill Holden, M.D.Lake Forest, IL 600451548289200
- Tanya Huang, M.D.Lake Forest, IL 600451134141989
- Michael Hubbell, M.D.Lake Forest, IL 600451538181268
- Rebecca Jacobson, MDLake Forest, IL 600451114902483
- Shayna Mancuso, D.O.Lake Forest, IL 600451558394510
Common questions
What is Karen J. Mass, MD's NPI number?
Karen J. Mass, MD's National Provider Identifier (NPI) is 1710179759, issued on Aug 14, 2007. An NPI identifies a provider in billing; it is not a license.
Where is Karen J. Mass, MD located?
The NPPES record lists a practice address at 840 S Waukegan RD Ste 208, Lake Forest, IL, 60045. Phone: (847) 295-0433. Providers update this record themselves, so call before visiting.
How can I verify Karen J. Mass, MD's license?
NPPES lists Illinois license number 036-093084, 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 Karen J. Mass, MD prescribe under Medicare Part D?
In 2024, Karen J. Mass, MD had 592 Medicare Part D claims for 189 beneficiaries; the average among obstetrics & gynecology physician prescribers was 165. 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.