Quick answers
- Does Grant H. Louie accept Medicare assignment?
- Yes. Medicare's clinician data says Grant H. Louie accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
- How many Medicare patients does Grant H. Louie see?
- In 2024, CMS data shows 855 Original Medicare patients and 230,796 services for Grant H. Louie. This counts Original Medicare only and measures volume, not quality.
- What is Grant H. Louie's NPI number?
- 1306013214. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Medicare activity in 2024
Official CMS public-use data for Grant H. Louie, data year 2024 (released May 21, 2026). It covers Original Medicare (fee-for-service) patients only, not Medicare Advantage or other insurance. It shows volume, not quality or outcomes. CMS hides any count of 10 or fewer patients.
| Original Medicare patients | 855 |
|---|---|
| Services billed to Medicare | 230,796 |
| Different services or procedures | 111 |
| Participating Medicare provider | Yes |
| Average age of these patients | 73 |
Most frequent services
- Injection, tocilizumab, 1 mg (J3262)63,920 services
- Injection, romosozumab-aqqg, 1 mg (J3111)22,680 services
- Injection, golimumab, 1 mg, for intravenous use (J1602)18,950 services
- Injection, denosumab, 1 mg (J0897)15,180 services
- Injection, mepolizumab, 1 mg (J2182)14,800 services
Chronic conditions among these patients
Share of this clinician’s Original Medicare patients with each condition, as published by CMS (it describes the patients, not the care given).
- High cholesterol75%
- Arthritis75%
- High blood pressure69%
- Osteoporosis46%
- Ischemic heart disease30%
- Anxiety30%
Hospitals where Grant H. Louie works
Medicare's Facility Affiliation Data lists Grant H. Louie at these hospitals (updated October 2, 2026). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians. Star rating and emergency services: Hospital General Information (CMS), data updated October 26, 2026.
- Frederick Health HospitalFrederick, MD · Acute Care Hospital · Medicare rating: 3 of 5 stars · Emergency services: listed by Medicare · CCN 210005
- WellSpan Waynesboro HospitalWaynesboro, PA · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 390138
Practice locations
Addresses where Grant H. Louie is enrolled with Medicare (CMS data updated October 2, 2026). The first 5 of 6; the Medicare profile lists all.
- 11110 Medical Campus RdHagerstown, MD 21742
- 14955 Shady Grove Rd, Suite 230Rockville, MD 20850 (301) 942‑7600
- 161 Thomas Johnson Dr, Suite 250Frederick, MD 21702
- 187 Thomas Johnson DrFrederick, MD 21702
- 187 Thomas Johnson Dr, Suite 6Frederick, MD 21702
Group practices
Medicare enrollment lists Grant H. Louie as a member of these groups (CMS data updated October 2, 2026).
- Meritus Medical Center Inc743 clinicians in the group
- Amber Hill Physical Therapy Inc334 clinicians in the group
- Arthritis and Rheumatism Associates PC50 clinicians in the group
Specialties
- Rheumatologyprimary
Other rheumatologists in Hagerstown
Clinicians with the same Medicare primary specialty in Hagerstown, MD — not a recommendation.
Other clinicians in Meritus Medical Center Inc
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Hahnemann University College Of Medicine |
| Graduation year | 2001 (25 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1306013214 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated October 2, 2026, retrieved October 29, 2026
- Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
- National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
- Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians