DANIEL MARK MERSON
DANIEL MARK MERSON is an organization registered with the National Plan and Provider Enumeration System (NPPES) under NPI 1003096017, based in Portland, ME. It is classified under Internal Medicine Physician.
Getting there
Here is what surrounds this office in Portland, based on OpenStreetMap data collected Sep 5, 2026. Parking is available about 470 ft away. The nearest transit stop is 0.30 mi away. If you arrive early, there is a coffee shop 0.38 mi away.
Getting here and what is nearby
Parking 136 ft ~1 min
Restaurant Subway 177 ft ~1 min
6 Allen Avenue, Portland 04103
Mo-Sa 10:00-22:00; Su 10:00-17:00
Parking 226 ft ~1 min
Restaurant McDonald's 201 ft ~1 min
Parking 470 ft ~2 min
Restaurant Babylon Restaurant 486 ft ~2 min
Gas station Sunoco 653 ft ~3 min
1185 Forest Avenue, Portland 04103
Transit 860 ft ~4 min
Convenience Cumberland Farms 0.21 mi ~5 min
1136 Forest Avenue, Portland 04103
Gas station Cumberland Farms 0.22 mi ~5 min
Transit 0.24 mi ~5 min
Transit 0.30 mi ~6 min
Coffee Starbucks 0.38 mi ~8 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 |
|---|---|---|
| ME1373 | ME | Internal Medicine Physician primary |
This provider holds licence ME1373 issued in ME. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.
This NPI does not appear in the PECOS Medicare enrolment file. Providers who do not bill Medicare — or who bill only through a group's enrolment — will not appear here. It is not a sign of any problem with the registration.
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-2 identifies an organization — a clinic, hospital, group practice, laboratory, or supplier. Individual clinicians working there hold their own NPI-1 numbers separately, so a bill may reference both.
| NPI | 1003096017 valid check digit |
|---|---|
| Entity type | Organization (NPI-2) |
| Enumeration date | Nov 7, 2007 |
| Last updated | Oct 16, 2008 |
| Status | Active |
| Practice address |
1250 FOREST AVE Portland, ME 04103 (207) 878-5042 Fax (207) 878-5043 |
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 | 0 | 9 | 6 | 0 | 1 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 0 | 0 | 3 | 0 | 9 | 3 | 0 | 2 |
Sum = 43 · next multiple of 10 = 50 · check digit = 7 · actual last digit = 7
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.