William Lacy, MD
NPI 1558457796 · Sleep Medicine (Internal Medicine) Physician · Louisville, KY
Enrolled with Medicare as Practitioner - Pulmonary Disease · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Lacy, MD is a Sleep Medicine (Internal Medicine) Physician provider in Louisville, KY (NPI 1558457796).
Provider details
- NPI number
- 1558457796
- Entity type
- Individual
- Primary specialty
- Sleep Medicine (Internal Medicine) PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- 28706 (KY)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
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
1,543 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) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 409 | $123 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 270 | $88 |
| Established Patient Office Or Other Outpatient Visit With High Level of Medical Decision Making, If Using Time, 40 Minutes Or More99215 | 125 | $167 |
| Home Sleep Test (hst) With Type III Portable Monitor, Unattended; Minimum of 4 Channels: 2 Respiratory Movement/Airflow, 1 Ecg/Heart Rate and 1 Oxygen SaturationG0399 | 119 | $101 |
| Test to Measure Expiratory Airflow and Volume94010 | 88 | $25 |
| Test to Determine Lung Volumes Using Sensors |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 38 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Fluticasone/Umeclidin/Vilanterbrand: Trelegy Ellipta | 1,055 | 212 |
| Albuterol Sulfatebrand: Albuterol Sulfate Hfa | 637 | 204 |
| Prednisone | 236 | 128 |
| Tiotropium Br/Olodaterol Hclbrand: Stiolto Respimat | 234 | 54 |
| Budesonide/Glycopyr/Formoterolbrand: Breztri Aerosphere | 227 | 50 |
| Albuterol Sulfatebrand: Ventolin Hfa | 197 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$564 across 8 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
- 2006-10-05
- Last updated
- 2024-11-20
- Certified
- 2024-11-20
Frequently asked questions
- What is William Lacy's NPI number?
- William Lacy's National Provider Identifier (NPI) is 1558457796, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Lacy's specialty?
- William Lacy is listed in the NPPES registry with a primary specialty of Sleep Medicine (Internal Medicine) Physician (Allopathic & Osteopathic Physicians).
- Where is William Lacy located?
- William Lacy's practice location on file with NPPES is 4606 Greenwood Rd, Louisville, KY 40258.
- What is William Lacy's phone number?
- The practice phone number listed in the NPPES registry for William Lacy is (502) 937-2209.
- Does William Lacy accept Medicare?
- William Lacy is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Lacy's NPI active?
- Yes — William Lacy's NPI (1558457796) is active in the NPPES registry as of the last update on 2024-11-20.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.