Day Lennep, M.D.
NPI 1538509955 · Internal Medicine Physician · Jackson, MS
Enrolled with Medicare as Practitioner - Rheumatology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Day Lennep, M.D. is a Internal Medicine Physician provider in Jackson, MS (NPI 1538509955).
Provider details
- NPI number
- 1538509955
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Female
- Sole proprietor
- No
- License
- T-2687 (MS)
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
13 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
7,840 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) |
|---|---|---|
| Insertion of Needle Into Vein for Collection of Blood Sample36415 | 1,124 | $9 |
| Complete Blood Cell Count (red Cells, White Blood Cell, Platelets), Automated Test and Automated Differential White Blood Cell Count85025 | 1,039 | $8 |
| Red Blood Cell Sedimentation Rate, to Detect Inflammation, Automated85652 | 1,038 | $3 |
| Blood Creatinine Level82565 | 1,015 | $5 |
| Liver Function Blood Test Panel80076 | 978 | $8 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 743 | $115 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 25 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Hydroxychloroquine Sulfate | 250 | 109 |
| Methotrexate Sodiumbrand: Methotrexate | 211 | 83 |
| Prednisone | 124 | 67 |
| Leflunomide | 53 | 20 |
| Adalimumabbrand: Humira(cf) Pen | 50 | — |
| Celecoxib | 42 | 20 |
| Etanerceptbrand: Enbrel Sureclick |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$2,538 across 148 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
- 2013-06-29
- Last updated
- 2013-06-29
Frequently asked questions
- What is Day Lennep's NPI number?
- Day Lennep's National Provider Identifier (NPI) is 1538509955, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Day Lennep's specialty?
- Day Lennep is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Day Lennep located?
- Day Lennep's practice location on file with NPPES is 2500 N State St, Jackson, MS 39216-4500.
- What is Day Lennep's phone number?
- The practice phone number listed in the NPPES registry for Day Lennep is (601) 984-5601.
- Does Day Lennep accept Medicare?
- Day Lennep is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Day Lennep's NPI active?
- Yes — Day Lennep's NPI (1538509955) is active in the NPPES registry as of the last update on 2013-06-29.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.