DR. KATHERINE ANN MASS MD
NPI 1437787801
Obstetrics & Gynecology in Glendale, WI
About Dr. Katherine Ann Mass Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. KATHERINE ANN MASS MD (NPI 1437787801) is an individual obstetrics & gynecology provider in Glendale, Wisconsin, licensed in Wisconsin (103890-875) and active in the NPI registry since March 2020. She is enrolled in Medicare PECOS, is affiliated with Essentia Health Virginia, and maintains a secondary practice location in Virginia.
NPPES Registry Identity
Specialties & Licenses
Secondary Practice Location 1
Other Identifiers 1
Accepted Insurance
Medicare Participation & PECOS CMS
Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.
Medicare Enrollment Status
Enrolled in Medicare and accepts Medicare assignment
Dr. Katherine Ann Mass Md is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.
Medicare Billing Reassignments
2Medicare enrollment records show Katherine Mass reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Duluth, MN 55807
- Reassigned Medicare billing, Minnesota enrollment
- 1,460 clinicians in this Medicare group
Alamosa, CO 81101
- Reassigned Medicare billing, Colorado enrollment
- 203 clinicians in this Medicare group
Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.
Hospital Affiliations CMS Care Compare
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
Essentia Health Virginia
Acute Care Hospitals · Virginia, MNPhysician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 53209 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
Other Providers at the Same Location NPPES 20
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
MILWAUKEE, WI 53209
Frequently Asked Questions NPPES & CMS
Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.
What is Katherine Mass's NPI number?
The NPI number for Katherine Mass is 1437787801. It was assigned to this individual provider in the NPPES registry on March 31, 2020.
Where is Katherine Mass located?
Katherine Mass practices at 3003 W Good Hope Rd, Glendale, WI 53209. The listed phone number is (414) 352-3100.
What is Katherine Mass's specialty?
The primary specialty registered for this NPI is Obstetrics & Gynecology with taxonomy code 207V00000X.
Is Katherine Mass enrolled in Medicare?
Yes. Katherine Mass is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.
Which organizations bill Medicare for Katherine Mass's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Katherine Mass reassigns Medicare benefits to 2 organizations: The Duluth Clinic Ltd (Duluth, MN) and Lutheran Hospital Association Of The San Luis Valley (Alamosa, CO). Each reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Katherine Mass's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does Katherine Mass accept?
Health plans from Anthem Blue Cross and Blue Shield, CareSource (Common Ground Healthcare) and UnitedHealthcare list Katherine Mass as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.
Is Katherine Mass affiliated with any hospitals?
According to CMS data, Katherine Mass is affiliated with Essentia Health Virginia.
When was this NPI record last updated?
The NPPES record for Katherine Mass was last updated on October 6, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 21 days ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.
# Dr. Katherine Ann Mass, MD · NPI 1437787801
Obstetrics & Gynecology physician in Glendale, Wisconsin. Individual provider, active in the CMS NPPES registry since March 31, 2020.
## Identity
- **NPI:** 1437787801 (Entity type: Individual)
- **Enumerated:** March 31, 2020
- **Primary specialty:** Obstetrics & Gynecology · taxonomy 207V00000X
- **State license:** 103890-875 (Wisconsin)
- **Sole proprietor:** No
## Practice location
- **Address:** 3003 W GOOD HOPE RD, Glendale, WI 53209-2042
- **Phone:** (414) 352-3100
## Medicare
- **Medicare:** Enrolled (PECOS); accepts Medicare assignment
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health, power mobility devices
- **Bills Medicare through:** 2 organizations under Medicare reassignment (form CMS-855R): The Duluth Clinic Ltd (NPI 1730028770, Duluth, MN); Lutheran Hospital Association Of The San Luis Valley (NPI 1720269434, Alamosa, CO) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Other, class of 2020
## Record status
- **NPPES last updated:** October 6, 2026
- **Other identifiers:** Medicaid 410883623 (WI)
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Source: [NPI Profile](https://npiprofile.com/npi/1437787801) · Data from the CMS NPPES public registry.