TAMMY YUE CHEN MD
Prescription History 1093887721
Family Medicine in Oakland, CA
What does Dr. Chen prescribe?
In 2024, Dr. Chen wrote 1,468 Medicare prescriptions for 39 medications. The most prescribed was Amlodipine Besylate, with 117 prescriptions for 54 patients.
Medicare Part D only. These are prescriptions filled by people with Medicare drug coverage in 2024, from the CMS data released in 2026, the most recent year available. CMS does not publish medications with fewer than 11 prescriptions, so this is not a full list of what Dr. Chen prescribes.
Medications 39 medications
Prescriptions filled under Medicare Part D in 2024. Select a medication to see what it is used for and how it compares with other California prescribers.
What it is used for
Amlodipine is used with or without other medications to treat high blood pressure.
Compared with California prescribers
Dr. Chen wrote 117 prescriptions for Amlodipine Besylate, about 83% as often as the typical California prescriber of it (141). Medicare paid $2.17 per fill, versus $7.08 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
Atorvastatin is used along with a proper diet to help lower "bad" cholesterol and fats (such as LDL, triglycerides) and raise "good" cholesterol (HDL) in the blood.
Compared with California prescribers
Dr. Chen wrote 109 prescriptions for Atorvastatin Calcium, about half as often as the typical California prescriber of it (202). Medicare paid $6.48 per fill, versus $10.47 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
Famotidine is used to treat ulcers of the stomach and intestines and to prevent intestinal ulcers from coming back after they have healed.
Compared with California prescribers
Dr. Chen wrote 109 prescriptions for Famotidine, about 2 times as often as the typical California prescriber of it (54). Medicare paid $7.82 per fill, versus $12.66 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
Baclofen is used to treat muscle spasms caused by certain conditions (such as multiple sclerosis, spinal cord injury/disease).
Compared with California prescribers
Dr. Chen wrote 97 prescriptions for Baclofen, about 2.3 times as often as the typical California prescriber of it (42). Medicare paid $3.48 per fill, versus $14.75 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
Albuterol (also known as salbutamol) is used to prevent and treat wheezing and shortness of breath caused by breathing problems (such as asthma, chronic obstructive pulmonary disease).
Compared with California prescribers
Dr. Chen wrote 86 prescriptions for Albuterol Sulfate Hfa, about 1.5 times as often as the typical California prescriber of it (58). Medicare paid $30.04 per fill, versus $28.70 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
Losartan is used to treat high blood pressure (hypertension) and to help protect the kidneys from damage due to diabetes.
Compared with California prescribers
Dr. Chen wrote 78 prescriptions for Losartan Potassium, about 64% as often as the typical California prescriber of it (121). Medicare paid $7.72 per fill, versus $10.35 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
Gabapentin is used with other medications to prevent and control seizures.
Compared with California prescribers
Dr. Chen wrote 62 prescriptions for Gabapentin, about 77% as often as the typical California prescriber of it (80). Medicare paid $9.50 per fill, versus $15.63 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
Fluticasone is used to relieve seasonal and year-round allergic and non-allergic nasal symptoms, such as stuffy/runny nose, itching, and sneezing.
Compared with California prescribers
Dr. Chen wrote 60 prescriptions for Fluticasone Propionate, about 1.2 times as often as the typical California prescriber of it (50). Medicare paid $9.08 per fill, versus $15.10 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
Lisinopril is used to treat high blood pressure.
Compared with California prescribers
Dr. Chen wrote 54 prescriptions for Lisinopril, about half as often as the typical California prescriber of it (98). Medicare paid $2.92 per fill, versus $8.30 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
This medication is used to treat a variety of skin conditions (such as insect bites, poison oak/ivy, eczema, dermatitis, allergies, rash, itching of the outer female genitals, anal itching).
Compared with California prescribers
Dr. Chen wrote 51 prescriptions for Hydrocortisone, about 1.8 times as often as the typical California prescriber of it (29). Medicare paid $3.55 per fill, versus $20.54 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
Meclizine is an antihistamine that is used to prevent and treat nausea, vomiting, and dizziness caused by motion sickness.
Compared with California prescribers
Dr. Chen wrote 44 prescriptions for Meclizine Hcl, about 1.2 times as often as the typical California prescriber of it (37). Medicare paid $3.22 per fill, versus $7.01 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
Metformin is used with a proper diet and exercise program and possibly with other medications to control high blood sugar.
Compared with California prescribers
Dr. Chen wrote 44 prescriptions for Metformin Hcl, about half as often as the typical California prescriber of it (100). Medicare paid $8.02 per fill, versus $9.26 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
This medication is used to treat a variety of skin conditions (such as eczema, dermatitis, allergies, rash).
Compared with California prescribers
Dr. Chen wrote 42 prescriptions for Triamcinolone Acetonide, about as often as the typical California prescriber of it (43). Medicare paid $5.09 per fill, versus $10.03 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
This medication is a beta-blocker used to treat chest pain (angina), heart failure, and high blood pressure.
Compared with California prescribers
Dr. Chen wrote 41 prescriptions for Metoprolol Succinate, about half as often as the typical California prescriber of it (86). Medicare paid $15.11 per fill, versus $14.23 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
See also Warning section.
Compared with California prescribers
Dr. Chen wrote 40 prescriptions for Diclofenac Sodium, about 85% as often as the typical California prescriber of it (47). Medicare paid $29.59 per fill, versus $107.23 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
This medication is used to treat depression.
Compared with California prescribers
Dr. Chen wrote 37 prescriptions for Trazodone Hcl, about 65% as often as the typical California prescriber of it (57). Medicare paid $3.26 per fill, versus $9.93 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
Ibuprofen is used to relieve pain from various conditions such as headache, dental pain, menstrual cramps, muscle aches, or arthritis.
Compared with California prescribers
Dr. Chen wrote 32 prescriptions for Ibuprofen, about 76% as often as the typical California prescriber of it (42). Medicare paid $2.85 per fill, versus $6.71 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
Alendronate is used to prevent and treat certain types of bone loss (osteoporosis) in adults.
Compared with California prescribers
Dr. Chen wrote 31 prescriptions for Alendronate Sodium, about half as often as the typical California prescriber of it (61). Medicare paid $4.28 per fill, versus $9.65 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
Omeprazole is used to treat certain stomach and esophagus problems (such as acid reflux, ulcers).
Compared with California prescribers
Dr. Chen wrote 26 prescriptions for Omeprazole, about 33% as often as the typical California prescriber of it (78). Medicare paid $5.76 per fill, versus $11.26 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
Glipizide is used with a proper diet and exercise program to control high blood sugar in people with type 2 diabetes.
Compared with California prescribers
Dr. Chen wrote 23 prescriptions for Glipizide, about half as often as the typical California prescriber of it (49). Medicare paid $6.86 per fill, versus $10.86 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
Sitagliptin is used with a proper diet and exercise program and possibly with other medications to control high blood sugar.
Compared with California prescribers
Dr. Chen wrote 23 prescriptions for Januvia, about half as often as the typical California prescriber of it (41). Medicare paid $1,416.04 per fill, versus $915.30 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
Metoprolol is used with or without other medications to treat high blood pressure (hypertension).
Compared with California prescribers
Dr. Chen wrote 22 prescriptions for Metoprolol Tartrate, about 39% as often as the typical California prescriber of it (57). Medicare paid $3.92 per fill, versus $7.82 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
Simvastatin is used along with a proper diet to help lower "bad" cholesterol and fats (such as LDL, triglycerides) and raise "good" cholesterol (HDL) in the blood.
Compared with California prescribers
Dr. Chen wrote 22 prescriptions for Simvastatin, about 35% as often as the typical California prescriber of it (63). Medicare paid $5.83 per fill, versus $9.03 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
Amoxicillin is used to treat a wide variety of bacterial infections.
Compared with California prescribers
Dr. Chen wrote 17 prescriptions for Amoxicillin, about half as often as the typical California prescriber of it (38). Medicare paid $3.32 per fill, versus $4.15 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
This medication is used to prevent and decrease symptoms (wheezing and trouble breathing) caused by asthma and ongoing lung disease (chronic obstructive pulmonary disease-COPD, including chronic bronchitis and emphysema).
Compared with California prescribers
Dr. Chen wrote 16 prescriptions for Breo Ellipta, about half as often as the typical California prescriber of it (32). Medicare paid $522.35 per fill, versus $491.19 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
This combination of nirmatrelvir and ritonavir is used to treat coronavirus disease (COVID-19) in people who have mild to moderate symptoms and have a high risk for COVID-19 complications.
Compared with California prescribers
Dr. Chen wrote 16 prescriptions for Paxlovid, about 66% as often as the typical California prescriber of it (24). Medicare paid $0.00 per fill, versus $42.82 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
Insulin glargine is used with a proper diet and exercise program to control high blood sugar in people with diabetes.
Compared with California prescribers
Dr. Chen wrote 15 prescriptions for Basaglar Kwikpen U-100, about half as often as the typical California prescriber of it (30). Medicare paid $297.96 per fill, versus $331.31 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
This medication is used to treat a wide variety of bacterial infections.
Compared with California prescribers
Dr. Chen wrote 15 prescriptions for Cephalexin, about half as often as the typical California prescriber of it (30). Medicare paid $3.82 per fill, versus $7.62 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
Furosemide is used to reduce extra fluid in the body (edema) caused by conditions such as heart failure, liver disease, and kidney disease.
Compared with California prescribers
Dr. Chen wrote 14 prescriptions for Furosemide, about 22% as often as the typical California prescriber of it (64). Medicare paid $2.38 per fill, versus $6.39 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
Insulin aspart is used with a proper diet and exercise program to control high blood sugar in people with diabetes.
Compared with California prescribers
Dr. Chen wrote 14 prescriptions for Novolog Flexpen, about half as often as the typical California prescriber of it (28). Medicare paid $133.62 per fill, versus $177.66 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
Dicyclomine is used to treat a certain type of intestinal problem called irritable bowel syndrome.
Compared with California prescribers
Dr. Chen wrote 13 prescriptions for Dicyclomine Hcl, about half as often as the typical California prescriber of it (27). Medicare paid $17.78 per fill, versus $17.05 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
Levothyroxine is used to treat an underactive thyroid (hypothyroidism).
Compared with California prescribers
Dr. Chen wrote 13 prescriptions for Levothyroxine Sodium, about 10% as often as the typical California prescriber of it (125). Medicare paid $7.98 per fill, versus $13.30 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
This medication is used to treat depression.
Compared with California prescribers
Dr. Chen wrote 13 prescriptions for Mirtazapine, about 32% as often as the typical California prescriber of it (40). Medicare paid $28.52 per fill, versus $19.05 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
Pantoprazole is used to treat certain stomach and esophagus problems (such as acid reflux).
Compared with California prescribers
Dr. Chen wrote 13 prescriptions for Pantoprazole Sodium, about 20% as often as the typical California prescriber of it (65). Medicare paid $7.17 per fill, versus $13.87 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
Prednisone is used to treat conditions such as arthritis, blood disorders, breathing problems, severe allergies, skin diseases, cancer, eye problems, and immune system disorders.
Compared with California prescribers
Dr. Chen wrote 13 prescriptions for Prednisone, about 32% as often as the typical California prescriber of it (40). Medicare paid $1.89 per fill, versus $5.64 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
This medication is used to prevent or treat gout attacks (flares).
Compared with California prescribers
Dr. Chen wrote 12 prescriptions for Colchicine, about half as often as the typical California prescriber of it (26). Medicare paid $21.97 per fill, versus $45.46 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
Levocetirizine is an antihistamine used to relieve allergy symptoms such as watery eyes, runny nose, itching eyes/nose, and sneezing.
Compared with California prescribers
Dr. Chen wrote 12 prescriptions for Levocetirizine Dihydrochloride, about 22% as often as the typical California prescriber of it (54). Medicare paid $7.66 per fill, versus $10.77 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
Atenolol is used with or without other medications to treat high blood pressure (hypertension).
Compared with California prescribers
Dr. Chen wrote 11 prescriptions for Atenolol, about 22% as often as the typical California prescriber of it (50). Medicare paid $1.69 per fill, versus $9.20 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
See also Warning section.
Compared with California prescribers
Dr. Chen wrote 11 prescriptions for Loperamide, about half as often as the typical California prescriber of it (23). Medicare paid $7.25 per fill, versus $15.35 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
Questions about Dr. Chen’s prescriptions
What does Dr. Chen prescribe most?
In 2024 Medicare Part D data, Dr. Chen's most prescribed medications were Amlodipine Besylate (117), Atorvastatin Calcium (109) and Famotidine (109).
How does Dr. Chen's prescribing compare with other California prescribers?
Of the 39 medications with a state comparison, Dr. Chen prescribes 4 more often than the typical California prescriber, 7 about as often and 28 less often. Volume reflects practice size as well as prescribing habits.
Does this list show every medication Dr. Chen prescribes?
No. It covers prescriptions filled by people with Medicare Part D drug coverage in 2024, and CMS leaves out any medication with fewer than 11 prescriptions.
About this data
This page shows one provider’s slice of public Medicare files. NPI Profile does not receive prescriptions or patient records.
| Source | What it provides here | Data year |
|---|---|---|
| CMS Medicare Part D Prescribers by Provider and Drug | Each medication, prescriptions, patients, 30-day fills, days of medication and cost. State comparisons average the California prescribers of the same medication and form, where at least five wrote it. | 2024 (released 2026, the most recent available) |
| CMS Medicare Part D Drug Spending Dashboard | What each medication is used for. | 2024 |
- Only prescriptions filled by people with Medicare Part D drug coverage are counted. Private insurance, Medicaid and cash purchases are not.
- CMS leaves out medications with fewer than 11 prescriptions and hides patient counts under 11.
- Cost per fill is what the plan and the patient paid the pharmacy together, not what you pay at the counter.
- Medication descriptions are summaries from CMS. They are not medical advice; ask a health care professional about any medication.
