Source: CMS Care Compare, October 2026 releaseER figures are medians, not live waitsAbout the data
Visiting Mark Twain Medical Center
San Andreas, CA 95249
County: Calaveras Directions Apple Maps Call (209) 754-3521
- Photo ID and your insurance, Medicare or Medicaid card
- A list of your medicines, doses and allergies
- Your doctor's name and phone number
- A phone charger
Nearest emergency rooms
- 12mi Sutter Amador Hospital Jackson, CA · Emergency room · median ER visit 2 hr 7 min Call Sutter Amador Hospital Directions to Sutter Amador Hospital (Google Maps) Details for Sutter Amador Hospital
- 22mi Sonora Regional Medical Center Sonora, CA · Emergency room · median ER visit 2 hr 56 min Call Sonora Regional Medical Center Directions to Sonora Regional Medical Center (Google Maps) Details for Sonora Regional Medical Center
- 32mi Oak Valley District Hospital Oakdale, CA · Emergency room · median ER visit 2 hr 34 min Call Oak Valley District Hospital Directions to Oak Valley District Hospital (Google Maps) Details for Oak Valley District Hospital
Quick answers about Mark Twain Medical Center
How long is the ER wait at Mark Twain Medical Center?
CMS doesn't publish live wait times. Over the 12 months CMS reported, patients treated and sent home spent a median of 1 hr 56 min in the Mark Twain Medical Center emergency room (the average across California hospitals is 3 hr). 1% of ER patients left before being seen. For tonight's wait, call (209) 754-3521. In an emergency, call 911.
What is the phone number for Mark Twain Medical Center?
The main phone number for Mark Twain Medical Center is (209) 754-3521, from Medicare's hospital records.
Call (209) 754-3521What is the address of Mark Twain Medical Center?
Mark Twain Medical Center is at 768 Mountain Ranch Rd, San Andreas, CA 95249.
Directions (opens Google Maps)Does Mark Twain Medical Center have an emergency room?
No emergency room is listed for Mark Twain Medical Center in Medicare data. For an emergency, call 911 or go to the nearest ER.
What is Mark Twain Medical Center's Medicare star rating?
Mark Twain Medical Center has an overall rating of 3 out of 5 stars from the Centers for Medicare & Medicaid Services (CMS). Star ratings come from CMS quality and safety measures, not patient reviews.
Quality and performance
Centers for Medicare & Medicaid Services · data as of October 2026
Patients treated and sent home from the emergency department at Mark Twain Medical Center spend a median of 1 hour 56 minutes there. That is 1 hour 4 minutes shorter than the average across California hospitals (3 hours).
Source: CMS Hospital General Information and Timely & Effective Care. Wait times are a median over a past 12-month reporting period, not live data. Not affiliated with CMS or with Mark Twain Medical Center. For a medical emergency, call 911.
Compare ER waits across California · How California hospitals rank on star ratings · Other Critical Access hospitals in California · How we source this data · Something wrong on this page? Tell us
What patients say
CMS patient survey (HCAHPS) · 150 completed surveys · patients discharged Jan 2025 – Dec 2025
Patients gave Mark Twain Medical Center a 4-star patient experience rating out of 5. 73% would definitely recommend it (U.S. average 71%). 80% rated it 9 or 10 out of 10.
The patient survey (HCAHPS) asks a random sample of adult patients about their recent hospital stay. CMS adjusts the results for the mix of patients and how the survey was done, so hospitals can be compared fairly. About the data.
Infections, complications and deaths
Centers for Medicare & Medicaid Services · compared with hospitals nationwide
Mark Twain Medical Center was no different from the national benchmark on the one hospital-acquired infection CMS could compare.
Hospital-acquired infections
Death rates within 30 days
| Patients treated for | This hospital | U.S. |
|---|---|---|
| Heart failure patients | 10.0% | 11.1% |
| Pneumonia patients | 17.9% | 15.2% |
| COPD patients | 9.3% | 8.6% |
| Hospital-wide, all conditions | 4.5% | 3.9% |
Risk-adjusted rates. CMS has not published a statistical better/worse comparison for these death rates in the current release, so small differences from the U.S. rate may be chance.
"Better" or "worse" means CMS found the difference from the national benchmark statistically significant; most hospitals are "no different". Infection results compare the infections a hospital reported with the number predicted for a hospital of its size and type (a ratio below 1 means fewer than predicted), for Jan 2025 – Dec 2025. Death and complication rates are risk-adjusted for how sick patients were. Each death rate counts deaths within 30 days of a hospital stay, pooled over one to three years of Medicare patients depending on the measure. About the data.
Health insurance at Mark Twain Medical Center
Original Medicare: Medicare-certified, so it can bill Original Medicare (Medicare number 051332). Medicare Advantage plans have their own networks, which this section does not cover.
California runs its own exchange, Covered California. Check its provider directory for Mark Twain Medical Center.
Source: the insurers' 2027 machine-readable provider files listed in the CMS Marketplace public use files, loaded November 4, 2026, matched to hospitals by NPI from CMS Hospital Enrollments. How we match networks to hospitals Networks change; confirm with your insurer before you go.
Readmissions and return visits
Centers for Medicare & Medicaid Services · Medicare patients · Jul 2024 – Jun 2025
On the 4 readmission and return-visit measures CMS could compare, Mark Twain Medical Center was no different from the national rate or its expected level.
Back in the hospital within 30 days
| After a stay for | This hospital | U.S. | CMS comparison |
|---|---|---|---|
| All conditions (hospital-wide)Medicare patients back in any hospital within 30 days of leaving. | 16.8% | 16.2% | Not compared |
| Heart failure | 21.2% | 21.3% | Not compared |
| Pneumonia | 16.8% | 17.3% | Not compared |
| COPD (chronic lung disease) | 19.8% | 20% | Not compared |
Return trips after a stay or procedure
Readmission rates count Medicare patients who were admitted to any acute-care hospital within 30 days of leaving this one, adjusted for how sick they were. "Better" or "worse" means CMS found the difference from the national rate statistically significant; most hospitals are "no different". Return-day and outpatient-surgery measures compare the hospital with what CMS expected for its own patients. The Readmissions Reduction Program ratios are shown as CMS publishes them; whether a hospital's payments are reduced depends on how its ratios compare with similar hospitals, so a ratio above 1.00 alone doesn't mean a penalty. About the data.
Timely and effective care
Centers for Medicare & Medicaid Services · all patients unless noted · Jan 2025 – Dec 2025
Mark Twain Medical Center's emergency department is classed by CMS as low volume.
| Measure | This hospital | U.S.* |
|---|---|---|
| Sepsis: got all recommended early treatmentPatients with severe sepsis or septic shock who received every step of the recommended early care bundle. Higher is better. 101 patients. | 75% | 66% |
| Septic shock: full treatment within 3 hoursHigher is better. 28 patients. | 82% | 75% |
| Typical time in the ER before going homeMedian minutes from arrival to leaving, for ER patients sent home (not counting mental health patients or transfers). Lower is better. 361 patients. | 116 min | 162 min |
| Typical ER time for mental health patients sent homeMedian minutes from arrival to leaving. Lower is better. 24 patients. | 236 min | 257 min |
| Typical ER time for patients transferred to another facilityMedian minutes from arrival to leaving. Lower is better. 15 patients. | 429 min | 287 min |
| Patients who left the ER before being seenLower is better. 11,681 patients. | 1% | 2% |
| Health care workers vaccinated against fluHigher is better. 379 patients. | 70% | 77% |
| Discharged on two opioids, or an opioid and a benzodiazepinePatients sent home with prescriptions that raise the risk of overdose when combined. Lower is better. 251 patients. | 10% | 16% |
| Colonoscopy: right follow-up interval for average-risk patientsHigher is better. 94 patients. | 95% | 93% |
| Blood clot prevention givenHigher is better. 492 patients. | 89% | 91%* |
| Blood clot prevention given in intensive careHigher is better. 274 patients. | 95% | 97%* |
| Stroke: discharged on clot-prevention medicineHigher is better. 39 patients. | 74% | 98%* |
CMS publishes these process-of-care measures without a better/worse verdict, so the U.S. figure is shown for context; small differences, or results based on few patients, may not mean much. *Median of all hospitals CMS reports, where CMS publishes no national figure. About the data.
Care after a stay at Mark Twain Medical Center
Medicare-certified providers near this hospital, with their CMS ratings. A hospital discharge planner can make the referral.
Skilled nursing facilities nearby
- <0.1mi Golden San Andreas Care Center San Andreas, CA · 99 beds Medicare overall 2 of 5 stars · Short-stay quality 2 of 5
- 12mi Kit Carson Nursing & Rehabilitation Center Jackson, CA · 199 beds Medicare overall 1 of 5 stars · Short-stay quality 4 of 5 SFF candidate
- 21mi Adventist Health Sonora - D/P SNF Sonora, CA · 68 beds Medicare overall 5 of 5 stars · Located in a hospital
Skilled nursing ratings and inspections at Nursing Homes In Each State
Dialysis centers nearby See more
- 12mi Innovative Renal Care JacksonJackson, CA
Home health agencies nearby See more
- 12mi United Home Care of Northern CaliforniaJackson, CA · 91% would recommend
- 23mi Adventist Health Home Care ServicesSonora, CA · 83% would recommend
Hospice care providers nearby See more
- 12mi Hospice of Amador & CalaverasJackson, CA · 98% would recommend
- 23mi Adventist Health Home Care ServicesSonora, CA · 91% would recommend
Source: CMS Care Compare. Distances are approximate.
Doctors at Mark Twain Medical Center
137 Medicare-enrolled doctors and other clinicians list this hospital as an affiliation, across 22 specialties.
Find doctors in San Andreas
Medicare-enrolled specialists with a practice in San Andreas, with addresses, phone numbers and the hospitals they work with.
Size and finances
Medicare cost report · fiscal year ending Dec 2024
As reported by the hospital to CMS; not audited. Operating margin is income from patient care divided by net patient revenue and leaves out investment income and donations. Compare California hospital finances.
Who owns Mark Twain Medical Center
Medicare enrollment and ownership records (PECOS)
Medicare lists the hospital's legal name as Mark Twain Medical Center, a non-profit organization, incorporated 1987.
205 doctors and other clinicians list Mark Twain Medical Center as a hospital affiliation in Medicare's clinician directory.
Organizations with 5% or more ownership (directly or through other companies), partnership interests or operational control, as the hospital reported them to Medicare. Records can lag behind recent sales. Individuals are not listed. Who owns America's hospitals.
Non-profit finances
IRS Form 990 · tax year ending Jun 2023 · Mark Twain Medical Center Foundation (EIN 68-0023507)
As filed with the IRS by Mark Twain Medical Center Foundation. Matched by name and address, so check the filing to confirm it's the right organization. See the full Form 990 filings · Non-profit hospital finances.
The area around Mark Twain Medical Center
HRSA shortage designations and BLS pay data
Primary care: Calaveras is a federally designated health professional shortage area. Highest shortage score 12.
Mental health: Calaveras is a federally designated health professional shortage area. Highest shortage score 15.
Nurse pay: registered nurses in California earn a median $140,270 a year. Healthcare salaries in California.
Shortage areas are designated by the Health Resources and Services Administration where there are too few primary care, mental health or dental providers for the population; scores run from 0 to 25 for primary and mental health care and 0 to 26 for dental care, higher meaning greater need. California shortage areas
Closest other hospitals
Healthcare pay in California
Registered nurses across California (all employers) earned a median of $140,270 a year (BLS, May 2025).Registered Nurse (RN) salary in CaliforniaNurse Practitioner salary in CaliforniaRespiratory Therapist salary in CaliforniaHealthcare salaries in California
Add this rating badge to your website
The badge updates automatically when CMS publishes new ratings. The compact and footer-strip sizes fit site footers and sidebars. All badge sizes and help.
Cite this data
Writing about Mark Twain Medical Center? You're welcome to quote these figures. They are free to use under CC BY 4.0: please credit HospitalsInEachState.com and link to this page.