Isaac Lill
Isaac Lill is an Internal Medicine Physician in Waco, TX, registered under NPI 1003558495.
Getting there
Here is what surrounds this office in Waco, based on OpenStreetMap data collected Oct 6, 2026. Parking is available about 714 ft away.
Getting here and what is nearby
Parking 284 ft ~2 min
Parking 670 ft ~3 min
Parking 714 ft ~3 min
Hotel Hilton Garden Inn 0.26 mi ~6 min
Restaurant P.F. Chang's 0.30 mi ~7 min
5511 Crosslake Parkway, Waco 76712
Su-Th 11:00-22:00; Fr-Sa 11:00-23:00
Restaurant Fish City Grill 0.33 mi ~7 min
5401 Crosslake Parkway, Waco 76712
Restaurant Los Cucos Mexican Cafe 0.33 mi ~7 min
2805 West Loop 340, Waco 76712
Hotel Holiday Inn Express & Suites Waco South 0.37 mi ~8 min
5701 Legend Lake Parkway, Waco 76712
Hotel TownePlace Suites Waco South 0.41 mi ~9 min
Distances are straight‑line estimates — walking routes may be longer. Hours and phone numbers can change; call ahead to confirm.
Credentials and Medicare
| Licence | State | Specialty |
|---|---|---|
| V6348 | TX | Internal Medicine Physician primary |
This provider holds licence V6348 issued in TX. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.
- Status
- Approved
- Provider type
- Practitioner - Internal Medicine
- PAC ID
- 0042714891
- Enrollment ID
- I20250916002904
Medicare enrolment is recorded as approved under the provider type Practitioner - Internal Medicine. Being enrolled means the provider can bill Medicare; it does not tell you whether they are currently accepting new Medicare patients. Call the office to confirm.
What Internal Medicine covers
A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs. NUCC Health Care Provider Taxonomy, code 207R00000X
The taxonomy records how the provider classifies their own practice. It does not confirm which conditions they currently treat, whether they are accepting new patients, or which insurance they take — call the office for that.
Full NPPES record
An NPI-1 identifies a single person. It stays with the clinician for life, even if they move practice or change state, which is why the address on file can lag behind where they actually work today.
| NPI | 1003558495 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Apr 7, 2022 |
| Last updated | Oct 1, 2025 |
| Status | Active |
| Sole proprietor | No |
| Gender | Male |
| Practice address |
100 HILLCREST MEDICAL BLVD Waco, TX 76712 (254) 202-2000 Fax (254) 202-5651 |
| Mailing address |
PO BOX 848491 Dallas, TX 75284 |
Number check
How the check works, step by step
Every NPI carries a Luhn check digit — the same scheme used on credit cards. CMS prefixes the number with 80840 before computing it, which marks it as a US health identifier.
| Digit | 8 | 0 | 8 | 4 | 0 | 1 | 0 | 0 | 3 | 5 | 5 | 8 | 4 | 9 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 0 | 0 | 3 | 1 | 5 | 7 | 4 | 9 |
Sum = 55 · next multiple of 10 = 60 · check digit = 5 · actual last digit = 5
A valid check digit only means the number is well-formed. It does not mean the provider is licensed, active, or in good standing — those are separate questions answered by the sections above.