CMS certification 200008
Northern Light Mercy Hospital
144 State Street, Portland, ME 04101
Northern Light Mercy Hospital has a CMS overall rating of 4 out of 5 stars. 85% of patients who answered CMS's national survey would definitely recommend it, against a US average of 71%. Of the 20 death, complication, infection and readmission measures CMS could compare, it does better than the nation on 1 and worse on 1. Emergency patients spend a median of 3 h 28 min in its emergency department before leaving (US median 2 h 42 min).
Every figure on this page is published by CMS; we arrange and explain it, and score nothing ourselves.
What patients said
Answers from patients who stayed here, collected by CMS in the national HCAHPS survey: 861 completed surveys, 31% response rate, Oct 2024 – Sep 2025.
Emergency department
How long emergency patients spent here and how some time-critical care went, from CMS's timely and effective care measures, Oct 2024 – Sep 2025. CMS classes this emergency department's patient volume as medium; busier departments tend to have longer times, so the national median for departments of the same volume is shown too. These are medians over a year of visits, not a live wait time.
| Measure | This hospital | ME | US |
|---|---|---|---|
| Median time in the emergency department before leaving Lower is better · 370 visits sampled · US median for EDs of the same volume: 2 h 45 min | 3 h 28 min | 2 h 40 min | 2 h 42 min |
| Median time for psychiatric and mental health patients Lower is better · 26 visits sampled | 5 h 42 min | 4 h 39 min | 4 h 17 min |
| Left before being seen Lower is better · 23,396 patients | 3% | 3% | 2% |
| Severe sepsis and septic shock: all recommended care given Higher is better · 246 patients | 43% | 62% | 65% |
How Northern Light Mercy Hospital compares with nearby hospitals
The closest hospitals of the same kind that CMS rates or surveys - the same city first, then the same county and ZIP area. Every figure is CMS's: the overall star rating, the share of patients who would definitely recommend the hospital, the median time emergency patients spent before leaving, and how many death, complication, infection and readmission measures CMS found better or worse than the national rate.
| Hospital | CMS stars | Would recommend | ER median time | Vs the nation |
|---|---|---|---|---|
| Northern Light Mercy HospitalThis hospital | 4/5 | 85% | 3 h 28 min | 1 better 1 worse |
| Mainehealth Maine Medical CenterSame city | 4/5 | 74% | 3 h 27 min | 3 better 1 worse |
| Mainehealth Mid Coast HospitalSame county · Brunswick | 3/5 | 74% | 3 h 16 min | 1 better 1 worse |
| Bridgton HospitalSame county · Bridgton | 3/5 | 61% | 1 h 58 min | No different |
Hospitals differ in size and in how sick their patients are. CMS adjusts its outcome measures for that, but a star or a percentage is a starting point for questions, not a verdict. All hospitals in Portland.
Deaths
How many patients died within 30 days of admission, adjusted by CMS for how sick they were. Lower is better. Data from Jul 2022 – Jun 2025.
| Measure | CMS comparison | This hospital | National |
|---|---|---|---|
| All patients, hospital-wide 1,314 cases | Too few cases | 3.5% | 3.9% |
| Heart failure 111 cases | Too few cases | 11.6% | 11.1% |
| Pneumonia 145 cases | Too few cases | 11.9% | 15.2% |
| Stroke 54 cases | Too few cases | 9.7% | 11.9% |
| COPD 33 cases | Too few cases | 7.6% | 8.6% |
2 more measures had too few cases here to report.
Complications
How often patients had serious complications, most of them after surgery, adjusted for how sick they were. Lower is better. Data from Jul 2022 – Jun 2024.
| Measure | CMS comparison | This hospital | National |
|---|---|---|---|
| Serious complications, combined measure | No different | 0.89 likely 0.46 – 1.33 | 1 |
| After hip or knee replacement 45 cases | Too few cases | 4.5% | 4.1% |
| Pressure ulcers (bed sores) 1,228 cases | No different | 0.4 per 1,000 likely 0 per 1,000 – 1.48 per 1,000 | 0.63 per 1,000 |
| Collapsed lung caused by a procedure 1,513 cases | No different | 0.26 per 1,000 likely 0.03 per 1,000 – 0.48 per 1,000 | 0.21 per 1,000 |
| Broken bones from falls in the hospital 1,449 cases | No different | 0.26 per 1,000 likely 0.04 per 1,000 – 0.47 per 1,000 | 0.27 per 1,000 |
| Bleeding or hematoma after surgery 365 cases | No different | 2.46 per 1,000 likely 0.79 per 1,000 – 4.12 per 1,000 | 2.34 per 1,000 |
| Kidney injury needing dialysis after surgery 207 cases | No different | 1.57 per 1,000 likely 0 per 1,000 – 3.25 per 1,000 | 1.67 per 1,000 |
| Breathing failure after surgery 206 cases | No different | 9.27 per 1,000 likely 0.43 per 1,000 – 18.12 per 1,000 | 9.42 per 1,000 |
| Blood clots in the lungs or legs after surgery 377 cases | No different | 2.96 per 1,000 likely 0.53 per 1,000 – 5.38 per 1,000 | 3.52 per 1,000 |
| Sepsis after surgery 171 cases | No different | 4.53 per 1,000 likely 0.49 per 1,000 – 8.57 per 1,000 | 5.27 per 1,000 |
| Surgical wound splitting open 110 cases | No different | 1.69 per 1,000 likely 0.19 per 1,000 – 3.2 per 1,000 | 1.77 per 1,000 |
| Accidental cut or tear during abdominal surgery 295 cases | No different | 1.51 per 1,000 likely 0.46 per 1,000 – 2.55 per 1,000 | 1.06 per 1,000 |
1 more measure had too few cases here to report.
Infections caught in the hospital
Standardized infection ratio: 1.0 means as many infections as CMS predicted for a hospital like this one. Lower is better. Data from Oct 2024 – Sep 2025.
| Measure | CMS comparison | This hospital | National |
|---|---|---|---|
| Bloodstream infections from central lines (CLABSI) | No different | 0 | 1 |
| Urinary tract infections from catheters (CAUTI) | No different | 0.88 likely 0.04 – 4.32 | 1 |
| Surgical site infections after colon surgery | No different | 0.85 likely 0.14 – 2.81 | 1 |
| MRSA bloodstream infections | No different | 0.94 likely 0.05 – 4.64 | 1 |
| C. diff intestinal infections | No different | 0.69 likely 0.28 – 1.43 | 1 |
1 more measure had too few cases here to report.
Readmissions and return visits
How often patients had to come back to a hospital after going home. Lower is better. Data from Jul 2023 – Jun 2025.
| Measure | CMS comparison | This hospital | National |
|---|---|---|---|
| Readmitted after heart failure 201 cases | Too few cases | 21.2% | 21.3% |
| Readmitted after pneumonia 274 cases | Too few cases | 17% | 17.3% |
| Readmitted after COPD 76 cases | Too few cases | 22% | 20% |
| Readmitted after hip or knee replacement 50 cases | Too few cases | 5.5% | 5.8% |
| Days back in hospital after heart failure 124 cases | Too few cases | 9.6 days per 100 | — |
| Days back in hospital after pneumonia 155 cases | Too few cases | -14.7 days per 100 | — |
| Unplanned visits after an outpatient colonoscopy 872 cases | No different | 13.2 per 1,000 likely 10.1 per 1,000 – 17.4 per 1,000 | 13 per 1,000 |
| Hospital admissions during outpatient chemotherapy 39 cases | No different | 10.4 per 100 likely 7.2 per 100 – 14.9 per 100 | 10.7 per 100 |
| ER visits during outpatient chemotherapy 39 cases | No different | 5.1 per 100 likely 3.3 per 100 – 8 per 100 | 5.4 per 100 |
| Unplanned visits after outpatient surgery 692 cases | No different | 1 likely 0.8 – 1.3 | — |
4 more measures had too few cases here to report.
Clinicians registered at this address
116 clinicians give this hospital's street address as their practice location in NPPES, the federal provider registry. The same address can take in offices and clinics in the building, and a listing does not prove admitting privileges or current employment.
| Specialty | Clinicians |
|---|---|
| Nurse Anesthetist, Certified Registered | 20 |
| Physician Assistant | 16 |
| Emergency Medicine | 10 |
| Internal Medicine | 8 |
| Anesthesiology | 7 |
| Clinical | 7 |
| Dietitian, Registered | 7 |
| Diagnostic Radiology | 6 |
| Family | 5 |
| Cardiovascular Disease | 3 |
| Nurse Practitioner | 2 |
| Psychiatric/Mental Health | 2 |
First 12 alphabetically
How to read this page
- Everything here is published by CMS on Care Compare. We arrange it and explain it; the star ratings and the better / worse verdicts are CMS's, not ours.
- “No different” is the most common result on most measures at most hospitals. CMS only calls a result better or worse when the difference from the national rate is statistically clear.
- Death, complication and readmission rates are adjusted by CMS for how sick patients were, so hospitals that treat sicker patients can be compared fairly.
- Infection results are ratios: 1.0 means as many infections as CMS predicted for a hospital like this one, below 1.0 is fewer.
- These are hospital-wide results. They do not rate an individual doctor, nurse or department, and they are not medical advice.
CMS Care Compare data retrieved 4 Oct 2026, refreshed weekly. Where this data comes from and how we handle it · Report an error
Common questions about Northern Light Mercy Hospital
Is Northern Light Mercy Hospital a good hospital?
Northern Light Mercy Hospital has a CMS overall rating of 4 out of 5 stars. Of the 20 death, complication, infection and readmission measures CMS could compare, it does better than the nation on 1 and worse on 1. These are hospital-wide results published by CMS; they do not rate individual doctors or departments.
Would patients recommend Northern Light Mercy Hospital?
85% of patients who answered CMS's national survey would definitely recommend it, against a US average of 71%. The figure comes from 861 completed HCAHPS surveys.
How long is the wait in the Northern Light Mercy Hospital emergency room?
Emergency patients spend a median of 3 h 28 min in its emergency department before leaving (US median 2 h 42 min). Among US emergency departments with medium patient volume, like this one, the median is 2 h 45 min. 3% of emergency patients left before being seen (US 2%). These are medians over a year of visits, not a live wait time.