Doctor profile · Federal record
Dr. John Walker, D.O.
Internal Medicine Physician (CMS: Gastroenterology) · Portland, ME
- NPI 1851737811
- Accepts Medicare
- 13 yrs in practice
- Male
- Group practice
- No sanctions
Practice & contact
- Primary practice
-
22 Bramhall St
Portland, ME 041023134
(207) 662-6562 - Mailing address
-
300 Southborough Dr, Suite 201
South Portland, ME 041066914
Credentials & registration
- NPI registered
- May 2013 — 13 yrs on file
- Profile last updated
- June 21, 2016
- Year of graduation
- 2013 — 13 yrs since
- Specialty taxonomy
- 207R00000X — NUCC code
- State license (1)
- Maine #DO2640
Federal sanctions & exclusions
No sanctions, exclusions or revocations on file
Checked against OIG LEIE on NPI 1851737811. Last verified May 11, 2026.Medicare procedures · 2023
Top services delivered
Total services
274
Distinct HCPCS
8
Medicare allowed
$32,470
| HCPCS | Description | Services | Patients | Avg allowed | |
|---|---|---|---|---|---|
45385 |
Removal of polyps or growths of large bowel using an endoscope with mechanical snare | 73 | 71 | $217 | |
43239 |
Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope | 58 | 55 | $84 | |
45380 |
Biopsy of large bowel using a flexible endoscope | 52 | 52 | $47 | |
99214 |
Established patient office or other outpatient visit, 30-39 minutes | 32 | 28 | $93 | |
99213 |
Established patient office or other outpatient visit, 20-29 minutes | 19 | 18 | $64 | |
99215 |
Established patient office or other outpatient visit, 40-54 minutes | 15 | 15 | $139 | |
43235 |
Diagnostic exam of esophagus, stomach, and/or upper small bowel using a flexible endoscope | 14 | 14 | $92 | |
45378 |
Diagnostic exam of large bowel using a flexible endoscope | 11 | 11 | $152 |
In context: peer comparison
Among 43 peers in Portland Internal Medicine Physician, average services per provider: 61. This provider delivers 4.5× the peer median.Medicare Part D · 2023
Top prescriptions
Total claims
606
Patients
291
Total drug cost
$70,591
| Drug | Type | Claims | Patients | Total cost |
|---|---|---|---|---|
| Peg 3350-Electrolyte (Sodium Chloride/Nahco3/Kcl/Peg) | Brand | 211 | 206 | $4,262 |
| Omeprazole | Generic | 171 | 68 | $3,475 |
| Pantoprazole Sodium | Generic | 51 | 17 | $2,014 |
| Carvedilol | Generic | 37 | 0 | $390 |
| Linzess (Linaclotide) | Brand | 28 | 0 | $30,821 |
| Budesonide Dr (Budesonide) | Brand | 20 | 0 | $12,962 |
| Mesalamine | Generic | 19 | 0 | $8,385 |
| Sulfasalazine | Generic | 15 | 0 | $574 |
| Budesonide Ec (Budesonide) | Brand | 14 | 0 | $4,066 |
| Furosemide | Generic | 14 | 0 | $79 |
Hospital affiliations
Frequently asked questions
What is Dr. John Walker's medical specialty?
Dr. John Walker practices Internal Medicine Physician in Portland, ME.
Where does Dr. John Walker practice?
Dr. John Walker practices at 22 Bramhall St, Portland, ME 041023134. Office phone: 2076626562.
What is Dr. John Walker's NPI?
Dr. John Walker's National Provider Identifier (NPI) is 1851737811, issued by NPPES.
Does Dr. John Walker accept Medicare assignment?
Yes. Dr. John Walker accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. John Walker commonly perform?
Top Medicare-reported procedures in 2023: Removal of polyps or growths of large bowel using an endoscope with mechanical snare (HCPCS 45385); Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope (HCPCS 43239); Biopsy of large bowel using a flexible endoscope (HCPCS 45380). Source: CMS Medicare Physician & Other Practitioners file.