Quick answers
- Does Douglas Y. Mah accept Medicare assignment?
- Yes. Medicare's clinician data says Douglas Y. Mah 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 Douglas Y. Mah see?
- In 2024, CMS data shows 80 Original Medicare patients and 132 services for Douglas Y. Mah. This counts Original Medicare only and measures volume, not quality.
- What is Douglas Y. Mah's NPI number?
- 1912062324. 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 Douglas Y. Mah, 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 | 80 |
|---|---|
| Services billed to Medicare | 132 |
| Different services or procedures | 24 |
| Participating Medicare provider | Yes |
| Average age of these patients | 42 |
Most frequent services
- Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report only (93010)63 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).
- Heart failure50%
- Anxiety44%
- High blood pressure39%
- High cholesterol39%
- Atrial fibrillation26%
- Depression25%
Hospitals where Douglas Y. Mah works
Medicare's Facility Affiliation Data lists Douglas Y. Mah 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.
- Boston Children's HospitalBoston, MA · Children's Hospital · Emergency services: listed by Medicare · CCN 223302
Practice locations
Addresses where Douglas Y. Mah is enrolled with Medicare (CMS data updated October 2, 2026).
- 300 Longwood AveBoston, MA 02115 (617) 355‑6000
Group practices
Medicare enrollment lists Douglas Y. Mah as a member of this group (CMS data updated October 2, 2026).
- Boston Childrens Heart Foundation Inc100 clinicians in the group
Specialties
Other pediatricians in Boston
Clinicians with the same Medicare primary specialty in Boston, MA — not a recommendation.
Other clinicians in Boston Childrens Heart Foundation Inc
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 2004 (22 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1912062324 |
| 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