Terence Ahern, MD
Emergency Medicine · Stanford
- Medicare standing
- Clear
- Enrolled, allowed to bill and order, not excluded
- Plans that list them
- Not verified
- Not the same as out of network.
- Office
- 1
Offices
1 location · Stanford Health Care · 3,152 clinicians in this group
Looking this up.
Hospitals listed: Stanford Health Care. That is not proof they admit you there this week.
Plan participation
Not verified
We could not verify current plan participation for this doctor. This does not mean they are out of network. Call Dr. Ahern’s office at (650) 723-4000 to ask if they take your plan before you enroll.
California Medical Board record
Licence A123764 · Current
Licensed to practise in California · since 2012 · expires 2026-12-31 · University of Southern California Keck School of Medicine.
No disciplinary actions, convictions, malpractice judgments or citations in this record.
Hospitals they work in
1 hospital
These rate the hospital, not this clinician. Most measures at most hospitals are no different from the national rate.
- Stanford Health CareStanford, CAAcute Care Hospital · Voluntary non-profit - Private · Has an emergency departmentPart of Stanford Health Care, which runs 3 hospitalsHome of Stanford Cancer Institute, a National Cancer Institute designated comprehensive cancer centrePatients rate it 4 of 5 · 83% would definitely recommend itOverall rating: 5 of 5 starsWorse than the national rate — Perioperative pulmonary embolism or deep vein thrombosis rate: 5.31 (4.24 to 6.37) · 8,661 cases, Jul 2022 – Jun 2024Worse than the national rate — Rate of inpatient admissions for patients receiving outpatient chemotherapy: 14.1 (12.7 to 15.7) · 2,191 cases, Jan 2024 – Dec 2024Better than the national rate — Postoperative respiratory failure rate: 4.08 (1.95 to 6.21) · 5,296 cases, Jul 2022 – Jun 2024Better than the national rate — Catheter Associated Urinary Tract Infections (ICU + select Wards): 0.317, Oct 2024 – Sep 2025Better than the national rate — Clostridium Difficile (C.Diff): 0.446, Oct 2024 – Sep 2025Better than the national rate — SSI - Colon Surgery: 0.241, Oct 2024 – Sep 2025Better than the national rate — Ratio of unplanned hospital visits after hospital outpatient surgery: 0.7 (0.6 to 0.9) · 3,348 cases, Jan 2024 – Dec 2024
See every measure and the patient survey for Stanford Health Care
Behind the star rating — Deaths: 5 better, 3 the same, 0 worse of 8 measures. Safety: 3 better, 5 the same, 0 worse of 8 measures. Readmissions: 2 better, 5 the same, 4 worse of 11 measures. The star rating is worked out from an earlier period than the measures below, so the two can disagree.
| Perioperative pulmonary embolism or deep vein thrombosis rateComplications and deaths | 5.31 (4.24 to 6.37) · 8,661 cases | Worse | Jul 2022 – Jun 2024 |
| Rate of inpatient admissions for patients receiving outpatient chemotherapyUnplanned return visits | 14.1 (12.7 to 15.7) · 2,191 cases | Worse | Jan 2024 – Dec 2024 |
| Postoperative respiratory failure rateComplications and deaths | 4.08 (1.95 to 6.21) · 5,296 cases | Better | Jul 2022 – Jun 2024 |
| Catheter Associated Urinary Tract Infections (ICU + select Wards)Infections | 0.317 | Better | Oct 2024 – Sep 2025 |
| Clostridium Difficile (C.Diff)Infections | 0.446 | Better | Oct 2024 – Sep 2025 |
| SSI - Colon SurgeryInfections | 0.241 | Better | Oct 2024 – Sep 2025 |
| Ratio of unplanned hospital visits after hospital outpatient surgeryUnplanned return visits | 0.7 (0.6 to 0.9) · 3,348 cases | Better | Jan 2024 – Dec 2024 |
| Abdominopelvic accidental puncture or laceration rateComplications and deaths | 1.06 (0.45 to 1.67) · 5,374 cases | No different | Jul 2022 – Jun 2024 |
| CMS Medicare PSI 90: Patient safety and adverse events compositeComplications and deaths | 0.86 (0.72 to 1) | No different | Jul 2022 – Jun 2024 |
| Death rate among surgical inpatients with serious treatable complicationsComplications and deaths | 166.09 (137.88 to 194.3) · 470 cases | No different | Jul 2022 – Jun 2024 |
| Death rate for CABG surgery patientsComplications and deaths | 1.1 · 192 cases | None | Jul 2022 – Jun 2025 |
| Death rate for COPD patientsComplications and deaths | 6.4 · 146 cases | None | Jul 2022 – Jun 2025 |
| Death rate for heart attack patientsComplications and deaths | 9.7 · 253 cases | None | Jul 2022 – Jun 2025 |
| Death rate for heart failure patientsComplications and deaths | 6.3 · 880 cases | None | Jul 2022 – Jun 2025 |
| Death rate for pneumonia patientsComplications and deaths | 10.3 · 935 cases | None | Jul 2022 – Jun 2025 |
| Death rate for stroke patientsComplications and deaths | 8.7 · 501 cases | None | Jul 2023 – Jun 2025 |
| Hybrid Hospital-Wide All-Cause Risk Standardized Mortality RateComplications and deaths | 2.1 · 7,730 cases | None | Jul 2024 – Jun 2025 |
| Iatrogenic pneumothorax rateComplications and deaths | 0.13 (0 to 0.27) · 20,799 cases | No different | Jul 2022 – Jun 2024 |
| In-hospital fall-associated fracture rateComplications and deaths | 0.28 (0.14 to 0.43) · 23,182 cases | No different | Jul 2022 – Jun 2024 |
| Postoperative acute kidney injury requiring dialysis rateComplications and deaths | 0.94 (0.2 to 1.68) · 5,694 cases | No different | Jul 2022 – Jun 2024 |
| Postoperative hemorrhage or hematoma rateComplications and deaths | 2.36 (1.54 to 3.19) · 7,846 cases | No different | Jul 2022 – Jun 2024 |
| Postoperative sepsis rateComplications and deaths | 5.2 (3.76 to 6.64) · 5,603 cases | No different | Jul 2022 – Jun 2024 |
| Postoperative wound dehiscence rateComplications and deaths | 1.38 (0.23 to 2.53) · 2,211 cases | No different | Jul 2022 – Jun 2024 |
| Pressure ulcer rateComplications and deaths | 0.52 (0.21 to 0.83) · 19,915 cases | No different | Jul 2022 – Jun 2024 |
| Rate of complications for hip/knee replacement patientsComplications and deaths | 3.6 · 416 cases | None | Apr 2023 – Mar 2025 |
| Central Line Associated Bloodstream Infection (ICU + select Wards)Infections | 0.869 | No different | Oct 2024 – Sep 2025 |
| MRSA BacteremiaInfections | 0.857 | No different | Oct 2024 – Sep 2025 |
| SSI - Abdominal HysterectomyInfections | 0.368 | No different | Oct 2024 – Sep 2025 |
| Acute Myocardial Infarction (AMI) 30-Day Readmission RateUnplanned return visits | 16.2 · 247 cases | None | Jul 2023 – Jun 2025 |
| Heart failure (HF) 30-Day Readmission RateUnplanned return visits | 20.5 · 1,021 cases | None | Jul 2023 – Jun 2025 |
| Hospital return days for heart attack patientsUnplanned return visits | 47.8 · 258 cases | None | Jul 2022 – Jun 2025 |
| Hospital return days for heart failure patientsUnplanned return visits | -1.6 · 990 cases | None | Jul 2022 – Jun 2025 |
| Hospital return days for pneumonia patientsUnplanned return visits | 20.8 · 976 cases | None | Jul 2022 – Jun 2025 |
| Pneumonia (PN) 30-Day Readmission RateUnplanned return visits | 16.5 · 959 cases | None | Jul 2023 – Jun 2025 |
| Rate of emergency department (ED) visits for patients receiving outpatient chemotherapyUnplanned return visits | 5.2 (4.4 to 6.2) · 2,191 cases | No different | Jan 2024 – Dec 2024 |
| Rate of readmission after hip/knee replacementUnplanned return visits | 5.1 · 425 cases | None | Jul 2023 – Jun 2025 |
| Rate of readmission for CABGUnplanned return visits | 9.6 · 158 cases | None | Jul 2023 – Jun 2025 |
| Rate of readmission for chronic obstructive pulmonary disease (COPD) patientsUnplanned return visits | 19.6 · 183 cases | None | Jul 2023 – Jun 2025 |
| Rate of unplanned hospital visits after colonoscopy (per 1,000 colonoscopies)Unplanned return visits | 12.7 (10.4 to 15.4) · 4,578 cases | No different | Jan 2022 – Dec 2024 |
What patients said (6,810 patients answered, 25% of those asked)
| Cleanliness | 4 |
| Nurse communication | 4 |
| Doctor communication | 4 |
| Communication about medicines | 3 |
| Discharge information | 4 |
| Overall hospital rating | 4 |
| Quietness | 2 |
| Recommend hospital | 5 |
| Room was "always" clean | 75% |
| Nurses "always" communicated well | 82% |
| Doctors "always" communicated well | 81% |
| Staff "always" explained | 63% |
| Yes, staff "did" give patients this information | 89% |
| Yes, staff "did" give patients information about help after discharge | 89% |
| Doctors "always" explained things so they could understand | 76% |
| Doctors "always" listened carefully | 80% |
| Doctors "always" treated them with courtesy and respect | 87% |
| Patients who gave a rating of "9" or "10" (high) | 79% |
| Staff "always" explained new medications | 76% |
| Nurses "always" explained things so they could understand | 77% |
| Nurses "always" listened carefully | 79% |
| Nurses "always" treated them with courtesy and respect | 88% |
| "Always" quiet at night | 53% |
| "YES", patients would definitely recommend the hospital | 83% |
| Staff "always" explained possible side effects | 50% |
| Yes, staff "did" give patients information about possible symptoms | 90% |
Original Medicare doctor bills
$79,442
Medicare paid this office $79,442 for 540 people.
This is what Medicare paid the clinician — not Medicare Advantage, and not the pharmacy.
| Emergency department visit with high level of medical decision making | 353 | $50,289 | $140 |
| Critical care, first 30-74 minutes | 88 | $15,191 | $171 |
| Emergency department visit with moderate level of medical decision making | 79 | $7,427 | $94 |
| Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report only | 112 | $782 | $6 |
| Ultrasound of heart, follow-up | 21 | $463 | $22 |
Who their Medicare patients are
540 Original Medicare patients in 2024. Average age 75 · Under 65 14% · 85 and older 21% · Women 54% · Also on Medicaid 39% · Health risk score 2.11. Above the middle of the specialty; the typical emergency medicine clinician is at 2.01.
Conditions among them: High blood pressure 75% · Coronary heart disease 42% · Chronic kidney disease 36% · Diabetes 35% · Heart failure 35% · Depression 32% · Atrial fibrillation 30% · COPD 25% · Dementia 20% · Cancer 19% · Stroke 18%.
The office billed $640,589, Medicare allowed $100,365 and paid $79,442; for 743 services of 43 kinds.
Original Medicare patients only. A risk score of 1.0 is the average Medicare patient; higher means sicker. Any count under 11 is hidden.
Year by year
| 2024 | 540 | 743 | 75 | 2.11 | $640,589 | $79,442 |
| 2023 | 534 | 848 | 74 | 1.92 | $753,723 | $81,227 |
| 2022 | 294 | 414 | 73 | 2.05 | $317,061 | $37,261 |
| 2021 | 240 | 296 | 76 | 1.18 | $70,893 | $26,449 |
| 2020 | 266 | 335 | 76 | 1.23 | $83,042 | $31,083 |
| 2019 | 282 | 350 | 75 | 1.24 | $96,226 | $31,568 |
| 2018 | 330 | 414 | 74 | 1.16 | $113,652 | $35,012 |
| 2017 | 334 | 418 | 74 | 1.13 | $113,159 | $36,537 |
| 2016 | 418 | 656 | 74 | 1.66 | $218,123 | $45,692 |
| 2015 | 233 | 406 | 70 | 2.32 | $155,634 | $28,011 |
| 2014 | 23 | 33 | 68 | 1.65 | $13,898 | $2,840 |
Original Medicare only. A service billed for fewer than 11 people in a year is hidden, so the lines can add up to less than the year's total.
See the services billed each year
2023: 5 services
| Emergency department visit with high level of medical decision making | 331 | $47,726 | $141 |
| Critical care, first 30-74 minutes | 99 | $17,102 | $173 |
| Emergency department visit with moderate level of medical decision making | 90 | $8,997 | $96 |
| Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report only | 214 | $1,498 | $7 |
| Emergency department visit with low level of medical decision making | 21 | $1,239 | $56 |
2022: 6 services
| Emergency department visit with high level of medical decision making | 181 | $24,569 | $134 |
| Critical care, first 30-74 minutes | 27 | $4,793 | $178 |
| Emergency department visit with moderate level of medical decision making | 46 | $4,072 | $89 |
| Emergency department visit with low level of medical decision making | 28 | $1,507 | $54 |
| Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report only | 82 | $580 | $7 |
| Emergency department visit with straightforward medical decision making | 12 | $290 | $24 |
2021: 4 services
| Emergency department visit with high level of medical decision making | 114 | $16,425 | $132 |
| Emergency department visit with moderate level of medical decision making | 49 | $3,746 | $76 |
| Emergency department visit with low level of medical decision making | 34 | $1,368 | $40 |
| Emergency department visit with straightforward medical decision making | 38 | $975 | $26 |
2020: 4 services
| Emergency department visit with high level of medical decision making | 131 | $18,624 | $132 |
| Emergency department visit with moderate level of medical decision making | 60 | $4,580 | $76 |
| Emergency department visit with low level of medical decision making | 37 | $1,813 | $48 |
| Emergency department visit with straightforward medical decision making | 36 | $1,116 | $29 |
2019: 4 services
| Emergency department visit with high level of medical decision making | 123 | $15,892 | $121 |
| Emergency department visit with moderate level of medical decision making | 120 | $9,448 | $77 |
| Emergency department visit with low level of medical decision making | 26 | $1,053 | $40 |
| Emergency department visit with straightforward medical decision making | 18 | $573 | $30 |
2018: 5 services
| Emergency department visit with high level of medical decision making | 145 | $18,159 | $118 |
| Emergency department visit with moderate level of medical decision making | 128 | $10,119 | $74 |
| Emergency department visit with low level of medical decision making | 50 | $1,855 | $37 |
| Critical care, first 30-74 minutes | 11 | $1,546 | $141 |
| Emergency department visit with straightforward medical decision making | 21 | $634 | $30 |
2017: 4 services
| Emergency department visit with high level of medical decision making | 143 | $19,009 | $120 |
| Emergency department visit with moderate level of medical decision making | 141 | $11,299 | $75 |
| Emergency department visit with straightforward medical decision making | 35 | $999 | $29 |
| Emergency department visit with low level of medical decision making | 21 | $889 | $42 |
2016: 6 services
| Emergency department visit with high level of medical decision making | 179 | $23,515 | $131 |
| Emergency department visit with moderate level of medical decision making | 144 | $12,209 | $84 |
| Critical care, first 30-74 minutes | 21 | $3,768 | $171 |
| Emergency department visit with low level of medical decision making | 54 | $2,224 | $41 |
| Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report only | 188 | $1,315 | $6 |
| Emergency department visit with straightforward medical decision making | 20 | $625 | $30 |
2015: 5 services
| Emergency department visit with high level of medical decision making | 117 | $15,859 | $134 |
| Emergency department visit with moderate level of medical decision making | 63 | $5,541 | $88 |
| Critical care, first 30-74 minutes | 17 | $2,973 | $175 |
| Emergency department visit with low level of medical decision making | 27 | $1,254 | $46 |
| Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report only | 143 | $1,040 | $7 |
2014: 1 service
| Emergency department visit with high level of medical decision making | 12 | $1,650 | $138 |
Medicaid work
$63,830 in 2024
Medicaid paid $63,830 for 847 billed services this clinician did in 2024, up to 55 people in a month for one service.
Medicaid and CHIP claims where this clinician did the service, fee-for-service and managed care together. Any month with fewer than 11 patients is hidden, so small Medicaid practices undercount.
| EMERGENCY DEPARTMENT VISIT HIGH MDM | 440 | $41,066 |
| EMERGENCY DEPT VISIT MOD MDM | 317 | $21,801 |
| Electrocardiogram, routine ECG with at least 12 leads; interpretation and report only | 90 | $962 |
| 2024 | 847 | 3 | 55 | $63,830 |
| 2023 | 1,341 | 6 | 54 | $80,891 |
| 2022 | 1,013 | 6 | 86 | $55,172 |
| 2020 | 14 | 1 | 13 | $1,725 |
| 2018 | 39 | 1 | 15 | $3,347 |
See the largest Medicaid services in earlier years
2023
| EMERGENCY DEPARTMENT VISIT HIGH MDM | 557 | $41,964 |
| EMERGENCY DEPT VISIT MOD MDM | 538 | $30,765 |
| EMERGENCY DEPT VISIT LOW MDM | 73 | $3,506 |
| Critical care, evaluation and management of the critically ill or critically injured patient; first 30-74 minutes | 14 | $1,913 |
| Service | 40 | $1,504 |
| Electrocardiogram, routine ECG with at least 12 leads; interpretation and report only | 119 | $1,240 |
2022
| EMERGENCY DEPARTMENT VISIT HIGH MDM | 255 | $23,569 |
| EMERGENCY DEPT VISIT MOD MDM | 302 | $19,429 |
| EMERGENCY DEPT VISIT LOW MDM | 188 | $7,958 |
| Electrocardiogram, routine ECG with at least 12 leads; interpretation and report only | 190 | $2,103 |
| Service | 52 | $2,099 |
| Service | 26 | $15 |
2020
| EMERGENCY DEPARTMENT VISIT HIGH MDM | 14 | $1,725 |
2018
| EMERGENCY DEPT VISIT MOD MDM | 39 | $3,347 |
Drugs they prescribed that Part D paid
$5,817
Pharmacies billed $5,817 in 2024.
This is pharmacy cost, not the office bill, and not what patients paid.
156 generic and fewer than 11 brand-name prescriptions · $5,817 in drug cost · 89 antibiotic prescriptions to 76 people.
Part D prescriptions only. The opioid rate is opioid prescriptions as a share of all this clinician's Part D prescriptions; surgeons and pain specialists run higher than others, so it is shown against the same specialty.
| Cephalexin | 35 | $236 | $7 |
| Ondansetron Odt | 11 | $138 | $12 |
| Azithromycin | 12 | $36 | $3 |
| Prednisone | 14 | $21 | $1 |
Year by year
| 2024 | 177 | 126 | None | None | $5,817 |
| 2023 | 198 | 145 | 14% (27) | None | $4,841 |
| 2022 | 59 | 46 | None | None | $1,113 |
| 2021 | 74 | 52 | None | None | $3,924 |
| 2020 | 71 | 54 | 20% (14) | 23% | $4,294 |
| 2019 | 75 | 60 | None | None | $2,811 |
| 2018 | 104 | 79 | 11% (11) | 13% | $2,674 |
| 2017 | 109 | 81 | 18% (20) | 15% | $3,738 |
| 2016 | 86 | 64 | 14% (12) | None | $3,009 |
| 2015 | 33 | 28 | None | None | $295 |
| 2014 | 32 | 21 | 44% (14) | None | $236 |
| 2013 | 26 | 15 | None | None | $537 |
Part D prescriptions only. A drug prescribed to fewer than 11 people in a year is hidden.
See the drugs prescribed each year
2023: 7 drugs
| Cephalexin | 30 | $253 | $8 |
| Doxycycline Hyclate | 16 | $151 | $9 |
| Ondansetron Odt | 11 | $142 | $13 |
| Amoxicillin-Clavulanate Potass | 13 | $120 | $9 |
| Azithromycin | 13 | $116 | $9 |
| Hydrocodone-Acetaminophen | 12 | $43 | $4 |
| Prednisone | 16 | $32 | $2 |
2019: 1 drug
| Cephalexin | 12 | $53 | $4 |
2018: 1 drug
| Cephalexin | 15 | $75 | $5 |
2017: 1 drug
| Cephalexin | 16 | $135 | $8 |
2014: 1 drug
| Hydrocodone-Acetaminophen | 13 | $80 | $6 |
Professional record
- NPI
- 1104195916
- Licence
- CA A123764, ID M-13191, OR MD170843California A123764: Current · expires 2026-12-31
- Group
- Stanford Health Care
- Gender
- Male
More record details
- Sole proprietor
- Yes
- Taxonomy
- Federal specialty code 207P00000X (207P00000X)
- Mailing address
- 300 Pasteur Dr, Palo Alto, CA, 94304
- NPI first listed
- 2011-12-22
- NPI last updated
- 2024-07-05
- NPI record certified
- 2024-07-05
This is when the NPI record was last certified, not a medical board exam.
Extra NPI addresses: 100 Hospital Drive, Ketchum, ID, 83340