Doctor profile · Federal record

Dr. Thalia Mayes, M.D.

Gastroenterology Physician (CMS: Gastroenterology) · Portland, ME

  • NPI 1033126826
  • Accepts Medicare
  • MIPS 93.1 / 100 · 2023
  • 24 yrs in practice
  • Female
  • Group practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
161 Marginal Way
Portland, ME 041012438
(207) 773-7964
fax (207) 773-9073

Credentials & registration

NPPES · NUCC
NPI registered
August 2006 — 20 yrs on file
Profile last updated
September 8, 2022
Year of graduation
2002 — 24 yrs since
Specialty taxonomy
207RG0100X — NUCC code
State license (1)
Maine #017618
Medicaid
ME #432967599

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1033126826. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
607
Distinct HCPCS
7
Medicare allowed
$54,472
HCPCS Description Services Patients Avg allowed
88305 Pathology examination of tissue using a microscope, intermediate complexity 264 82 $72
G0500 Moderate sedation services provided by the same physician or other qualified health care professional performing a gastrointestinal endoscopic service that sedation supports, requiring the presence of an independent trained observer to assist in the monito 76 75 $5
45385 Removal of polyps or growths of large bowel using an endoscope with mechanical snare 74 73 $242
45380 Biopsy of large bowel using a flexible endoscope 60 60 $66
99213 Established patient office or other outpatient visit, 20-29 minutes 50 43 $85
43239 Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope 44 43 $94
99214 Established patient office or other outpatient visit, 30-39 minutes 39 29 $123

In context: peer comparison

Among 14 peers in Portland Gastroenterology Physician, average services per provider: 56. This provider delivers 11× the peer median.

Open Payments

Industry payments received

CMS Open Payments
All-time total
$86
Transactions
1
Manufacturers
1
Payer (manufacturer) Industry Txns Amount
Lilly USA, LLC 1 $86.00

By nature of payment

Food and Beverage
$86

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
242
Patients
88
Total drug cost
$531,382
Drug Type Claims Patients Total cost
Omeprazole Generic 88 39 $1,117
Gavilyte-G (Peg3350/Sod Sulf,Bicarb,Cl/Kcl) Brand 55 49 $907
Ursodiol Generic 30 0 $8,198
Pantoprazole Sodium Generic 22 0 $539
Stelara (Ustekinumab) Brand 20 0 $515,015
Famotidine Generic 15 0 $266
Mesalamine ER (Mesalamine) Brand 12 0 $5,340

Hospital affiliations

CMS Hospital Compare

Frequently asked questions

Auto-generated from federal data
What is Dr. Thalia Mayes's medical specialty?
Dr. Thalia Mayes practices Gastroenterology Physician in Portland, ME.
Where does Dr. Thalia Mayes practice?
Dr. Thalia Mayes practices at 161 Marginal Way, Portland, ME 041012438. Office phone: 2077737964.
What is Dr. Thalia Mayes's NPI?
Dr. Thalia Mayes's National Provider Identifier (NPI) is 1033126826, issued by NPPES.
Does Dr. Thalia Mayes accept Medicare assignment?
Yes. Dr. Thalia Mayes accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Thalia Mayes commonly perform?
Top Medicare-reported procedures in 2023: Pathology examination of tissue using a microscope, intermediate complexity (HCPCS 88305); Moderate sedation services provided by the same physician or other qualified health care professional performing a gastrointestinal endoscopic service that sedation supports, requiring the presence of an independent trained observer to assist in the monito (HCPCS G0500); Removal of polyps or growths of large bowel using an endoscope with mechanical snare (HCPCS 45385). Source: CMS Medicare Physician & Other Practitioners file.