Physician Profile
Marylyn V. Grondin, M.D.
Unclaimed ProfileAbout Dr. Grondin
Marylyn V. Grondin, M.D. is a healthcare provider in Portsmouth, NH specializing in gastroenterology. Medicare claims data shows Marylyn provided 694 services to 647 patients. The services billed most often include established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more, colorectal cancer screening; colonoscopy on individual at high risk, and biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope. This provider record is associated with NPI 1841266327.
Factual summary compiled by Guide.md from public records; not written by this provider.
Education & Training
Specialty
Credentials & Licensing
Medicare information
Exactly as CMS reports it (National Downloadable File, Opt-Out Affidavits, Order & Referring). Not an insurance directory; confirm coverage with the office.
Contact Information
- (603) 433-2488
- Email not available
Practice Locations
330 BORTHWICK AVE SUITE 311
Portsmouth, NH 03801
Conditions Commonly Evaluated or Treated
Within Gastroenterology generally. Availability varies by clinician, training and location — this profile has not been claimed, so nothing here is a personal claim by the provider.
Conditions
Most searched conditions
- Acid reflux
- Celiac disease
- Crohn's disease
- Hemorrhoids
- IBS
- Swallowing difficulties
- Ulcerative colitis
Biliary and pancreas
- Acute pancreatitis
- Gallstones
- Pancreatic cysts
- Primary sclerosing cholangitis
Colon and anorectal
Esophagus and swallowing
- Barrett's esophagus
- Eosinophilic esophagitis
- Esophageal stricture
- Esophagitis
Functional bowel and motility
- Chronic diarrhea
- Fecal incontinence
- Small intestinal bacterial overgrowth
Liver
- Ascites
- Autoimmune hepatitis
- Cirrhosis
- Fatty liver disease
- Hemochromatosis
- Hepatitis B
- Hepatitis C
- Portal hypertension
Stomach and duodenum
- Functional dyspepsia
- Gastritis
- Gastroparesis
- H. pylori infection
- Peptic ulcer disease
Bowel & Colon
Digestive Symptoms
- Constipation
Gallbladder & Bile Ducts
- Blocked Bile Duct
Procedures & services
Most searched procedures
- Colonoscopy
- Endoscopy
- Gallbladder removal
- Hernia repair
- Liver biopsy
Lower endoscopy
- Colon polyp removal
- Endoscopic control of gastrointestinal bleeding
- Flexible sigmoidoscopy
Upper endoscopy
- Endoscopic submucosal dissection
- Esophageal dilation
Capsule and physiology testing
- Anorectal manometry
- Capsule endoscopy
- Esophageal manometry
Diagnostic Testing
- 24-Hour Acid Reflux Test
- EUS-Guided Fine Needle Biopsy
- H. Pylori Breath Test
- SIBO Breath Test
Liver procedures
- Esophageal variceal banding
- Liver elastography
- Paracentesis
Treatments
Procedures Most Often Billed to Medicare
694 services · 647 patients · 13 distinct codes
| Procedure | Type | Code | Services | Compared with peers |
|---|---|---|---|---|
| Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope | Procedure | 43239 |
78 | More often than most peers in Gastroenterology |
| Removal of polyps or growths of large bowel using an endoscope with mechanical snare | Procedure | 45385 |
67 | As often as other peers in Gastroenterology |
| Biopsy of large bowel using a flexible endoscope | Procedure | 45380 |
25 | Less often than most peers in Gastroenterology |
| Balloon dilation of esophagus, stomach, and/or upper small bowel using a flexible endoscope, less than 3.0 cm | Procedure | 43249 |
23 | As often as other peers in Gastroenterology |
| Diagnostic exam of large bowel using a flexible endoscope | Procedure | 45378 |
19 | As often as other peers in Gastroenterology |
| Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more | Office visit | 99213 |
213 | More than most peers in Gastroenterology |
| Colorectal cancer screening; colonoscopy on individual at high risk | Billing code | G0105 |
98 | More than most peers in Gastroenterology |
| New patient office or other outpatient visit with low level of medical decision making, if using time, 30 minutes or more | Office visit | 99203 |
55 | More often than most peers in Gastroenterology |
| Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more | Office visit | 99214 |
35 | Less often than most peers in Gastroenterology |
| Colorectal cancer screening; colonoscopy on individual not meeting criteria for high risk | Billing code | G0121 |
30 | More often than most peers in Gastroenterology |
Source: CMS Medicare public data. Shows how often procedures were billed — not quality of care or patient satisfaction.
Related providers
Connections drawn from the registry and from what providers have told us. A link here is not a referral or an endorsement.
Related specialists at this location 1
Clinically related specialties at the same address — the people this provider most likely works alongside.
Also at this address 4
Providers at the same street address. Each files their own registry entry, so a shared practice often appears under several different names.
Other gastroenterologists in Portsmouth 3
Same specialty, same city.
More connections — 23 related providers in 3 groups
Trained at Other 8
Other providers in the same specialty who trained at the same institution.
Class of 1978 at Other 8
Providers who graduated from the same medical school in the same year.
Also performs Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope 7
Providers in NH who bill this service to Medicare most often.
Common questions
What does Marylyn V. Grondin specialize in?
Marylyn V. Grondin is a gastroenterologist in Portsmouth, NH. That is the designation recorded for this NPI in the federal registry, where it is listed as “Gastroenterology”.
NPI registry
Where is Marylyn V. Grondin located?
Marylyn V. Grondin is listed at 330 Borthwick Ave Suite 311, Portsmouth, NH 03801. Addresses come from the NPI registry and can lag a move, so confirm before travelling.
NPI registry
What is Marylyn V. Grondin's phone number?
The number on file is (603) 433-2488. Contact the office directly to confirm availability and scheduling.
NPI registry
What is the NPI for Marylyn V. Grondin?
Marylyn V. Grondin's National Provider Identifier is 1841266327. It is issued by the Centers for Medicare & Medicaid Services and is unique and permanent — it does not change if they move practice.
NPI registry
Where did Marylyn V. Grondin train?
Marylyn V. Grondin attended Other, graduating in 1978. This comes from the CMS National Downloadable File.
CMS public data
How much experience does Marylyn V. Grondin have?
Marylyn V. Grondin has 48 years experience. Calculated from a graduation year of 1978, reported in the CMS National Downloadable File.
CMS public data
What does Marylyn V. Grondin do most often?
According to Medicare billing data, Marylyn V. Grondin performs procedures including biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope, removal of polyps or growths of large bowel using an endoscope with mechanical snare and biopsy of large bowel using a flexible endoscope, alongside routine visits and testing. This reflects Medicare patients only and is billing volume, not a measure of quality.
Medicare claims
Is Marylyn V. Grondin's profile verified?
Not yet. This profile is built from public federal data and has not been confirmed by Marylyn V. Grondin. If this is you, claiming it is free.
Guide.md
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