Allison Alden Merz-Heralla, MD
Obstetrics/Gynecology · San Francisco
- Medicare standing
- Clear
- Enrolled, allowed to bill and order, not excluded
- Plans that list them
- 9
- 1 carrier
- Office
- 1
Offices
1 location · University of California Sfgh Medical Group · 566 clinicians in this group
Looking this up.
Hospitals listed: Zuckerberg San Francisco General Hosp & Trauma Ctr. That is not proof they admit you there this week.
Plans that list them
9 plans · 1 carrier
A missing listing does not mean out of network. Directories change, and a listing does not cover every office. Call Dr. Merz-Heralla’s office at (628) 206-3409 to confirm they take your plan. Ask about the office you use, its medical group, referrals and appointments.
| Alignment Health BreathEasy (HMO C-SNP) | Alignment Health Plan | Listed | Oct 3, 2026 |
| Alignment Health Clarity (HMO C-SNP) | Alignment Health Plan | Listed | Oct 3, 2026 |
| Alignment Health Harmony (HMO) | Alignment Health Plan | Listed | Oct 3, 2026 |
| Alignment Health Heart & Diabetes (HMO C-SNP) | Alignment Health Plan | Listed | Oct 3, 2026 |
| Alignment Health Heart & Diabetes CalPlus (HMO C-SNP) | Alignment Health Plan | Listed | Oct 3, 2026 |
| Alignment Health Heart & Diabetes Care (HMO C-SNP) | Alignment Health Plan | Listed | Sep 28, 2026 |
| Alignment Health Heart & Diabetes Choice (HMO C-SNP) | Alignment Health Plan | Listed | Sep 28, 2026 |
| Alignment Health Honor+ Plan (HMO) | Alignment Health Plan | Listed | Oct 3, 2026 |
| Alignment Health My Choice CalCare (HMO) | Alignment Health Plan | Listed | Oct 3, 2026 |
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.
- Zuckerberg San Francisco General Hosp & Trauma CtrSan Francisco, CAAcute Care Hospital · Government - Local · Has an emergency department · Birthing-friendlyPart of San Francisco Health Network, which runs 2 hospitalsPatients rate it 3 of 5 · 72% would definitely recommend itOverall rating: 2 of 5 starsBetter than the national rate — Catheter Associated Urinary Tract Infections (ICU + select Wards): 0.449, Oct 2024 – Sep 2025Better than the national rate — Central Line Associated Bloodstream Infection (ICU + select Wards): 0.37, Oct 2024 – Sep 2025Better than the national rate — Clostridium Difficile (C.Diff): 0.538, Oct 2024 – Sep 2025
See every measure and the patient survey for Zuckerberg San Francisco General Hosp & Trauma Ctr
Behind the star rating — Deaths: 1 better, 6 the same, 0 worse of 7 measures. Safety: 1 better, 5 the same, 1 worse of 7 measures. Readmissions: 0 better, 7 the same, 2 worse of 9 measures. The star rating is worked out from an earlier period than the measures below, so the two can disagree.
| Catheter Associated Urinary Tract Infections (ICU + select Wards)Infections | 0.449 | Better | Oct 2024 – Sep 2025 |
| Central Line Associated Bloodstream Infection (ICU + select Wards)Infections | 0.37 | Better | Oct 2024 – Sep 2025 |
| Clostridium Difficile (C.Diff)Infections | 0.538 | Better | Oct 2024 – Sep 2025 |
| Abdominopelvic accidental puncture or laceration rateComplications and deaths | 0.9 (0 to 1.91) · 667 cases | No different | Jul 2022 – Jun 2024 |
| CMS Medicare PSI 90: Patient safety and adverse events compositeComplications and deaths | 1.12 (0.76 to 1.49) | No different | Jul 2022 – Jun 2024 |
| Death rate among surgical inpatients with serious treatable complicationsComplications and deaths | 195.34 (147.34 to 243.34) · 76 cases | No different | Jul 2022 – Jun 2024 |
| Death rate for COPD patientsComplications and deaths | 7.2 · 114 cases | None | Jul 2022 – Jun 2025 |
| Death rate for heart attack patientsComplications and deaths | 12.2 · 48 cases | None | Jul 2022 – Jun 2025 |
| Death rate for heart failure patientsComplications and deaths | 7.5 · 201 cases | None | Jul 2022 – Jun 2025 |
| Death rate for pneumonia patientsComplications and deaths | 14.5 · 214 cases | None | Jul 2022 – Jun 2025 |
| Death rate for stroke patientsComplications and deaths | 10.3 · 261 cases | None | Jul 2023 – Jun 2025 |
| Hybrid Hospital-Wide All-Cause Risk Standardized Mortality RateComplications and deaths | 3.5 · 1,351 cases | None | Jul 2024 – Jun 2025 |
| Iatrogenic pneumothorax rateComplications and deaths | 0.29 (0.07 to 0.5) · 4,709 cases | No different | Jul 2022 – Jun 2024 |
| In-hospital fall-associated fracture rateComplications and deaths | 0.39 (0.19 to 0.59) · 4,644 cases | No different | Jul 2022 – Jun 2024 |
| Perioperative pulmonary embolism or deep vein thrombosis rateComplications and deaths | 4.34 (2.11 to 6.56) · 795 cases | No different | Jul 2022 – Jun 2024 |
| Postoperative acute kidney injury requiring dialysis rateComplications and deaths | 1.59 (0 to 3.28) · 234 cases | No different | Jul 2022 – Jun 2024 |
| Postoperative hemorrhage or hematoma rateComplications and deaths | 2.85 (1.33 to 4.38) · 861 cases | No different | Jul 2022 – Jun 2024 |
| Postoperative respiratory failure rateComplications and deaths | 8.95 (0.25 to 17.64) · 261 cases | No different | Jul 2022 – Jun 2024 |
| Postoperative sepsis rateComplications and deaths | 6 (2.01 to 9.98) · 242 cases | No different | Jul 2022 – Jun 2024 |
| Postoperative wound dehiscence rateComplications and deaths | 1.66 (0.17 to 3.14) · 167 cases | No different | Jul 2022 – Jun 2024 |
| Pressure ulcer rateComplications and deaths | 0.79 (0.08 to 1.49) · 4,129 cases | No different | Jul 2022 – Jun 2024 |
| Rate of complications for hip/knee replacement patientsComplications and deaths | 4.4 · 35 cases | None | Apr 2023 – Mar 2025 |
| MRSA BacteremiaInfections | 0.709 | No different | Oct 2024 – Sep 2025 |
| SSI - Colon SurgeryInfections | 1.769 | No different | Oct 2024 – Sep 2025 |
| Acute Myocardial Infarction (AMI) 30-Day Readmission RateUnplanned return visits | 14.7 · 41 cases | None | Jul 2023 – Jun 2025 |
| Heart failure (HF) 30-Day Readmission RateUnplanned return visits | 22.1 · 227 cases | None | Jul 2023 – Jun 2025 |
| Hospital return days for heart failure patientsUnplanned return visits | 28.6 · 257 cases | None | Jul 2022 – Jun 2025 |
| Hospital return days for pneumonia patientsUnplanned return visits | 75.1 · 239 cases | None | Jul 2022 – Jun 2025 |
| Pneumonia (PN) 30-Day Readmission RateUnplanned return visits | 18.2 · 232 cases | None | Jul 2023 – Jun 2025 |
| Rate of emergency department (ED) visits for patients receiving outpatient chemotherapyUnplanned return visits | 6.8 (4.7 to 9.6) · 175 cases | No different | Jan 2024 – Dec 2024 |
| Rate of inpatient admissions for patients receiving outpatient chemotherapyUnplanned return visits | 11.3 (8.3 to 15.1) · 175 cases | No different | Jan 2024 – Dec 2024 |
| Rate of readmission after hip/knee replacementUnplanned return visits | 6.1 · 37 cases | None | Jul 2023 – Jun 2025 |
| Rate of readmission for chronic obstructive pulmonary disease (COPD) patientsUnplanned return visits | 20.2 · 132 cases | None | Jul 2023 – Jun 2025 |
| Rate of unplanned hospital visits after colonoscopy (per 1,000 colonoscopies)Unplanned return visits | 13.6 (10.4 to 17.9) · 966 cases | No different | Jan 2022 – Dec 2024 |
| Ratio of unplanned hospital visits after hospital outpatient surgeryUnplanned return visits | 1.2 (0.8 to 1.7) · 88 cases | No different | Jan 2024 – Dec 2024 |
What patients said (1,644 patients answered, 16% of those asked)
| Cleanliness | 4 |
| Nurse communication | 2 |
| Doctor communication | 3 |
| Communication about medicines | 2 |
| Discharge information | 3 |
| Overall hospital rating | 4 |
| Quietness | 3 |
| Recommend hospital | 4 |
| Room was "always" clean | 69% |
| Nurses "always" communicated well | 73% |
| Doctors "always" communicated well | 75% |
| Staff "always" explained | 56% |
| Yes, staff "did" give patients this information | 84% |
| Yes, staff "did" give patients information about help after discharge | 83% |
| Doctors "always" explained things so they could understand | 68% |
| Doctors "always" listened carefully | 75% |
| Doctors "always" treated them with courtesy and respect | 82% |
| Patients who gave a rating of "9" or "10" (high) | 72% |
| Staff "always" explained new medications | 67% |
| Nurses "always" explained things so they could understand | 68% |
| Nurses "always" listened carefully | 70% |
| Nurses "always" treated them with courtesy and respect | 80% |
| "Always" quiet at night | 55% |
| "YES", patients would definitely recommend the hospital | 72% |
| Staff "always" explained possible side effects | 44% |
| Yes, staff "did" give patients information about possible symptoms | 84% |
Professional record
- NPI
- 1770112492
- Trained
- Harvard Medical School, 2020
- Gender
- Female
More record details
- Sole proprietor
- Yes
- Taxonomy
- Federal specialty code 207VC0300X (207VC0300X); Federal specialty code 207V00000X (207V00000X)
- Mailing address
- 300 Pasteur Dr, Stanford, CA, 94305
- NPI first listed
- 2020-04-04
- NPI last updated
- 2026-09-14
- NPI record certified
- 2026-09-14
This is when the NPI record was last certified, not a medical board exam.
Extra NPI addresses: 3288 Moanalua Rd, Honolulu, HI, 96819