Mary Hammack, MD
NPI 1871501874 · Internal Medicine Physician · Plano, TX
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Mary Hammack, MD is a Internal Medicine Physician provider in Plano, TX (NPI 1871501874).
Provider details
- NPI number
- 1871501874
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Female
- Sole proprietor
- No
- License
- H6269 (TX)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
19 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
12,752 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
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 .
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) |
|---|---|---|
| Management Using the Results of Remote Vital Sign Monitoring Per Calendar Month, Each Additional 20 Minutes99458 | 2,266 | $38 |
| Chronic Care Management Services for Two Or More Chronic Conditions, Additional 20 Minutes of Clinical Staff Time Directed By Health Care Professional, Per Calendar Month99439 | 1,235 | $46 |
| Management Using the Results of Remote Vital Sign Monitoring Per Calendar Month, First 20 Minutes99457 | 1,138 | $46 |
| Remote Monitoring of Physiologic Parameters, Initial Supply of Devices With Daily Recordings Or Programmed Alerts Transmission, Each 30 Days99454 | 956 | $44 |
| Chronic Care Management Services, First 20 Minutes of Clinical Staff Time Directed By Health Care Professional, Per Calendar Month99490 | 680 | $49 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 137 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Levothyroxine Sodium | 573 | 147 |
| Atorvastatin Calcium | 475 | 131 |
| Escitalopram Oxalate | 250 | 54 |
| Amlodipine Besylate | 223 | 65 |
| Losartan Potassium | 211 | 58 |
| Gabapentin | 205 | 63 |
| Metoprolol Succinate |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$360 across 18 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-08-04
- Last updated
- 2008-12-23
Frequently asked questions
- What is Mary Hammack's NPI number?
- Mary Hammack's National Provider Identifier (NPI) is 1871501874, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mary Hammack's specialty?
- Mary Hammack is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Mary Hammack located?
- Mary Hammack's practice location on file with NPPES is 6124 W Parker Rd, Plano, TX 75093-8124.
- What is Mary Hammack's phone number?
- The practice phone number listed in the NPPES registry for Mary Hammack is (972) 981-7500.
- Does Mary Hammack accept Medicare?
- Mary Hammack is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Mary Hammack's NPI active?
- Yes — Mary Hammack's NPI (1871501874) is active in the NPPES registry as of the last update on 2008-12-23.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.