Katarzyna Mastalerz, M.D.
NPI 1861514275 · Hospitalist Physician · Denver, CO
Enrolled with Medicare as Practitioner - Hospitalist · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Katarzyna Mastalerz, M.D. is a Hospitalist Physician provider in Denver, CO (NPI 1861514275).
Provider details
- NPI number
- 1861514275
- Entity type
- Individual
- Primary specialty
- Hospitalist PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Female
- Sole proprietor
- No
- License
- 48931 (CO)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
19 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
2 documented practice locations
- Medicare service volume (vs. specialty peers)28% of score
74 Medicare services, 2024 (ranked within specialty)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 50 Minutes99233 | 54 | $116 |
| Initial Hospital Care With Moderate Level of Medical Decision Making, If Using Time, at Least 75 Minutes99223 | 20 | $170 |
Typical Medicare-allowed amounts for these services range $116–$170 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
Practice location
Mailing address
Additional practice locations (1)
- 12605 E 16th AveAurora, CO 80045-2545Phone: (720) 848-0000
Registry dates
- Enumerated
- 2007-04-04
- Last updated
- 2023-03-15
- Certified
- 2023-03-15
Frequently asked questions
- What is Katarzyna Mastalerz's NPI number?
- Katarzyna Mastalerz's National Provider Identifier (NPI) is 1861514275, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Katarzyna Mastalerz's specialty?
- Katarzyna Mastalerz is listed in the NPPES registry with a primary specialty of Hospitalist Physician (Allopathic & Osteopathic Physicians).
- Where is Katarzyna Mastalerz located?
- Katarzyna Mastalerz's practice location on file with NPPES is 1721 E 19th Ave, Denver, CO 80218-1243.
- What is Katarzyna Mastalerz's phone number?
- The practice phone number listed in the NPPES registry for Katarzyna Mastalerz is (303) 869-2440.
- Does Katarzyna Mastalerz accept Medicare?
- Katarzyna Mastalerz is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Katarzyna Mastalerz's NPI active?
- Yes — Katarzyna Mastalerz's NPI (1861514275) is active in the NPPES registry as of the last update on 2023-03-15.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.