Filing a Medical Misdiagnosis Claim

A woman in a mustard cardigan gestures as she talks to a gray-bearded doctor in a white coat, who listens with his hands clasped

In short

A misdiagnosis, a delayed diagnosis or a missed one can be malpractice when a reasonably careful provider in the same field would have made the right diagnosis sooner and the error caused you harm. A wrong or late diagnosis alone isn't enough: Michigan jurors can be told that 'a doctor is not liable merely because of an adverse result' (M Civ JI 30.04).
Cancers, vascular events such as strokes and heart attacks, and infections, the 'Big Three', accounted for about three-quarters of the diagnostic-error malpractice cases involving serious permanent harm or death in a 2019 study of 10 years of closed claims (Newman-Toker and others, Diagnosis, 2019; BMJ Quality & Safety, 2024).
You must show what a timely diagnosis would have changed. In Michigan, you can't recover for a lost opportunity to survive or to get a better result unless it was greater than 50%, but the Michigan Supreme Court has held that this limit doesn't apply to a traditional malpractice claim, in which you prove the negligence more probably than not caused your injury (MCL 600.2912a(2); O'Neal v St John Hospital, 2010).
Take care of your health first, then request your complete records in writing, including images, test results and the dates they were reported. Under HIPAA, a provider must act within 30 days, with one 30-day extension, and can charge only a reasonable, cost-based fee (45 CFR 164.524).
In Michigan, the two-year deadline generally runs from the missed diagnosis, but you may have six months from when you discovered or should have discovered the claim, if that ends later. Each provider generally must get a notice of intent at least 182 days before you sue, and for 2026, noneconomic damages are capped at $596,400, or $1,065,000 for three permanent injuries the statute lists (MCL 600.5838a, 600.2912b, 600.1483; Michigan Department of Treasury).

If a doctor said it was nothing and it turned out to be cancer, a heart attack, a stroke or a serious infection, you may be wondering what might have been. If you’re angry, frightened or asking whether you should have pushed harder, that’s a normal reaction.

Here’s the short answer. You may have a claim if a reasonably careful provider in the same field would have made the right diagnosis sooner and the delay made your outcome worse. A wrong or late diagnosis isn’t malpractice by itself: you have to show what should have happened and what difference it would have made. Take care of your health first, then get your records and write down the timeline.

The hard part is the process. The proof sits in records you don’t have yet, it usually takes a medical expert to say what they show, and in Michigan the two-year clock generally starts at the missed diagnosis, not when you find out (MCL 600.5838a(1)). Michigan’s rules, current as of September 28, 2026, are in the boxes marked “In Michigan.”

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What’s the difference between a misdiagnosis, a delayed diagnosis and a missed diagnosis?

A 2015 report from the National Academies of Sciences, Engineering, and Medicine defines a diagnostic error as “the failure to (a) establish an accurate and timely explanation of the patient’s health problem(s) or (b) communicate that explanation to the patient.” Timely depends on the condition: for an urgent one, it can mean minutes to hours (National Academies, 2015). Errors take three main forms:

A misdiagnosis is the wrong answer. The Patient Safety Network of the federal Agency for Healthcare Research and Quality (AHRQ PSNet) gives the example of crushing chest pain treated as a heart attack despite signs of an aortic dissection, a tear in the wall of the main artery leaving the heart (MedlinePlus).
A delayed diagnosis is the right answer, reached later than it should have been.
A missed diagnosis is one that wasn’t made at all, until someone else found the illness or it caused serious harm.

Is every wrong or late diagnosis malpractice?

No. A doctor forms a working diagnosis, which may be a list of possible causes called a differential diagnosis, and refines it as information comes in; doctors don’t need certainty before starting treatment (National Academies, 2015). So a first diagnosis that turns out wrong isn’t automatically malpractice. The question is whether a reasonably careful provider in the same field, in the same circumstances, would have considered the right condition and tested for it sooner. That’s the standard of care (Legal Information Institute; in Michigan, M Civ JI 30.01). Michigan jurors can also be told that “a doctor is not liable merely because of an adverse result” (M Civ JI 30.04).

Questions that help show whether the care fell short:

Did your symptoms call for a test, a referral or a follow-up visit?
Was the right test ordered, and was it read correctly?
Was an abnormal result followed up and passed on to you? Death or serious injury from a failure to follow up on or communicate a lab, pathology or radiology result is on the National Quality Forum’s list of serious reportable events (AHRQ PSNet).

A wrong diagnosis can also lead to the wrong treatment; see how medication error claims work. If a complication after an operation was missed, see what to do after a surgical error.

Which missed diagnoses cause the most serious harm?

AHRQ PSNet notes that missed or delayed diagnoses, particularly of cancer, are a prominent reason for malpractice claims. Researchers group the conditions behind the most serious harm into the “Big Three”: cancers, vascular events such as strokes and heart attacks, and infections such as sepsis.

In malpractice claims: in 10 years of closed malpractice claims (2006 to 2015) from a database covering about 30% of U.S. claims, the Big Three accounted for about three-quarters of the diagnostic-error cases involving serious permanent harm or death (Newman-Toker and others, Diagnosis, 2019; BMJ Quality & Safety, 2024).
Across U.S. health care: a follow-up study published in 2024, based on disease-incidence data from 2012 to 2014, estimated that about 795,000 Americans a year die or are permanently disabled because a dangerous disease is misdiagnosed in a clinic, emergency department or hospital (about 371,000 deaths and 424,000 permanent disabilities; plausible range 598,000 to 1,023,000). Stroke, sepsis, pneumonia, blood clots in the veins and lung cancer accounted for 38.7% of those harms (Newman-Toker and others, BMJ Quality & Safety, 2024).
In outpatient care: a 2014 study estimated that about 1 in 20 U.S. adults, roughly 12 million a year, experience a diagnostic error in outpatient care, and that about half of those errors could potentially be harmful (Singh and others, BMJ Quality & Safety, 2014).

These are national estimates. Only a review of your own records can show whether your diagnosis was missed.

What do you have to prove in a misdiagnosis claim?

Malpractice is professional negligence, so you generally have to prove its elements (Legal Information Institute; in Michigan, M Civ JI 30.03):

Duty: the provider was treating you, so it owed you professional care.
Breach: the care fell below the standard of care.
Causation: the error or delay caused harm that timely care would have avoided.
Damages: real losses, such as harder treatment, a worse outlook, lost income or a death in the family.

Causation turns on a medical question: what would have happened if the condition had been found in time? For a cancer, that can mean the stage it would have been found at; for a stroke or heart attack, whether earlier treatment would have limited the damage. Each side usually hires its own experts, who are paid for their time (Legal Information Institute).

Some states let you recover for a lost chance, the chance of a better outcome that the negligence took away. Massachusetts’ highest court allowed it when a doctor’s failure to diagnose a man’s stomach cancer in time cost him a chance of survival that was already less than even (Matsuyama v Birnbaum, 2008). Michigan’s rule is stricter.

In Michigan: You must prove your injury "more probably than not" was caused by the negligence, and "the plaintiff cannot recover for loss of an opportunity to survive or an opportunity to achieve a better result unless the opportunity was greater than 50%" (MCL 600.2912a(2)). In O'Neal v St John Hospital (2010), where a complication of sickle cell disease was allegedly misdiagnosed as pneumonia, the Michigan Supreme Court held that the 50% sentence applies only to lost-opportunity claims, not to a traditional malpractice claim, in which you prove the negligence more probably than not caused the injury. In Stone v Williamson (2008), all seven justices upheld a verdict for a man whose abdominal aortic aneurysm went undetected until it ruptured, but they split over what the 50% sentence means. In 2011, the committee that drafts Michigan's model jury instructions deleted its instruction on the rule, citing "a lack of consensus among the courts" (M Civ JI 30.20). Raise it with a lawyer early.

What evidence matters in a misdiagnosis case?

Your complete records. Ask every provider involved, in writing, for visit notes, test and pathology results, imaging reports and the images themselves, referrals and portal messages. Dates matter, too: when each test was ordered, when the result came back, and when and how you were told. Under the federal HIPAA Privacy Rule, you have a right to copies of your medical and billing records; a provider must act within 30 days, with one 30-day extension if it explains the delay in writing, and can charge only a reasonable, cost-based fee (45 CFR 164.501, 164.524).

A second opinion. It’s first about your health: a specialist can confirm the diagnosis and the treatment plan. It can also be where you learn that an earlier test may have been misread, as in the Michigan case below.

A timeline. List every visit, call, test and prescription, with dates, names, symptoms and what you were told. Note when you first learned, or suspected, that the diagnosis was missed; in Michigan, that date can decide whether the six-month rule helps you (MCL 600.5838a(2)).

A doctor in a white coat, a stethoscope around the neck, writes on a clipboard at a desk beside a keyboard

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What are Michigan’s rules for a misdiagnosis claim?

Every state sets its own deadline, and some add steps before you can sue; see injury deadlines in every state. Here are Michigan’s rules in brief. For each step in order, see Michigan medical malpractice law.

The notice of intent and the 182-day wait

The affidavit of merit

Who can serve as the expert

How long you have

In Michigan, as of September 28, 2026:

Most claims: 2 years from the act or omission, such as the visit or test reading where the diagnosis was missed, even if you didn't know about it (MCL 600.5805(8), 600.5838a(1)).
If you found out later: 6 months from when you discovered, or should have discovered, the claim, if that ends later. You must prove you didn't, and shouldn't have, discovered it at least 6 months before the 2 years ran out (MCL 600.5838a(2)). The six months start when, based on objective facts, you know or should know of an injury and a possible link to something a provider did or didn't do; you don't need to be certain you have a claim (Solowy v Oakwood Hospital, 1997).
An example: in Bowman v St John Hospital (2021), a woman diagnosed with metastatic breast cancer in 2015 learned from a specialist in August 2016 that her 2013 mammogram, read as showing benign cysts, might have been misread. The Michigan Supreme Court let the claim go forward at that early stage because the record didn't show she should have known sooner, though facts that would make a reasonable patient wonder whether a provider was responsible call for diligent follow-up.
Outer limit: generally 6 years after the act or omission, unless the provider's fraud hid the claim, a reproductive injury left you unable to have children, or a special rule for young children applies. A child under 8 at the time has until the 10th birthday, or the regular deadline if later (MCL 600.5838a(2), (3); 600.5851(7), (8)).
The notice period: if your deadline would pass during it, a notice sent in time pauses the clock for up to the days left in the notice period (MCL 600.5856(c)).

The cap on damages

What if a missed diagnosis led to a death?

The family’s claim is usually a wrongful death claim; see how wrongful death claims work.

In Michigan: The estate's personal representative (the person appointed to handle the estate) brings the claim, and damages can include medical and funeral costs, conscious pain and suffering, and the family's loss of financial support and companionship (MCL 600.2922(2), (6)); loss of companionship counts toward the cap (MCL 600.1483(3)). If the person died before their deadline ran out, or within 30 days after, the personal representative can sue within two years after the first letters of authority (the appointment papers) are issued, but no later than three years after the original deadline (MCL 600.5852). On July 29, 2026, in Ernest v Brown, where an estate alleged that a man who went to an emergency department with chest pain wasn't properly diagnosed and treated, and he died the next day, the Michigan Supreme Court held that a notice of intent pauses that extra time too, overruling Waltz v Wyse (2004). See Michigan wrongful death claims.

What to do next

Get the care you need now. If your trust in a provider is shaken, ask for a referral or a second opinion. In an emergency, call 911.
Request your complete records in writing from every provider involved, and keep a copy of each request.
Write your timeline, including when you first learned, or suspected, that the diagnosis was missed.
Find your deadline, and start early. In Michigan, the notice of intent must go out before the deadline passes, and preparing it takes your records and, in practice, an expert’s review. See every Michigan injury deadline in one place.
Get a case review, and the fee in writing. Get a free case review, or if you were treated in Michigan, compare Michigan injury lawyers. Get any fee agreement in writing; see how injury lawyers get paid. For a quick self-check first, see what to do if you think you have a malpractice case.

What waiting can cost

The claim itself. In Michigan, a malpractice suit filed too late “is barred” (MCL 600.5838a(2)).
The six months. Once facts point to an injury and a possible link to a provider’s care, the discovery window can start running (Solowy, 1997).
The pause. A notice of intent stops the clock only if it goes out before the deadline passes (MCL 600.5856(c)).
Evidence and time. Memories fade, and records requests, an expert’s review and the 182-day notice period all take time.

What a good outcome looks like

You’re getting the treatment you need from doctors you trust. Your records are in hand, and qualified experts have told you whether the diagnosis should have come sooner and what difference that made. If it should have, every provider got a proper notice in time, the lawsuit was filed with a sound affidavit of merit before the deadline, and those responsible pay for your care, lost income and what you went through, within Michigan’s limits. If not, you have a clear answer and can focus on getting well. From wondering whether it should have been caught to knowing what your records show, what an earlier diagnosis would have changed and when your deadline falls.

For other kinds of medical mistakes, see the complete medical malpractice guide or browse all medical malpractice guides.

Frequently asked questions

Can you sue a doctor for a misdiagnosis?

Yes, if the diagnosis fell below the standard of care and that caused you real harm. A wrong or late diagnosis isn't malpractice by itself: Michigan jurors can be told that 'a doctor is not liable merely because of an adverse result' (M Civ JI 30.04). You generally have to show what a reasonably careful provider in the same field would have done and what difference it would have made. In Michigan, the lawsuit must be filed with a qualified expert's affidavit of merit (MCL 600.2912d).

What is the difference between a misdiagnosis and a delayed diagnosis?

A misdiagnosis is the wrong answer: you're told you have one condition when you have another. A delayed diagnosis is the right answer, reached later than it should have been, and a missed diagnosis is one that wasn't made at all. A 2015 National Academies report covers all three in one definition of diagnostic error: a failure to establish an accurate and timely explanation of the patient's health problem, or to communicate that explanation to the patient.

What if my illness might have gotten worse even with an earlier diagnosis?

Then the claim may be about a lost chance: the chance of a better outcome that the delay took away. Some states allow recovery even for a chance below 50% (Matsuyama v Birnbaum, Massachusetts, 2008). Michigan's statute says a plaintiff 'cannot recover for loss of an opportunity to survive or an opportunity to achieve a better result unless the opportunity was greater than 50%' (MCL 600.2912a(2)). But the Michigan Supreme Court has held that this limit applies only to lost-opportunity claims, not to a traditional claim in which you prove the negligence more probably than not caused your injury, even if you faced some risk of that injury anyway (O'Neal v St John Hospital, 2010). Courts have disagreed about how to apply the 50% rule (M Civ JI 30.20).

How long do I have to file a misdiagnosis claim in Michigan?

Generally two years from the act or omission, such as the visit or test reading where the diagnosis was missed, or six months after you discovered or should have discovered the claim, whichever is later, and generally no more than six years after the act or omission (MCL 600.5805(8), 600.5838a). The six months start when, based on objective facts, you know or should know of an injury and a possible link to a provider's care (Solowy v Oakwood Hospital, 1997). Each provider generally must get a notice of intent at least 182 days before you sue (MCL 600.2912b), and children and deaths have their own rules (MCL 600.5851(7), (8); 600.5852).

How do I get my medical records and test results?

Ask each provider in writing for your complete records, including imaging, test and pathology results, and portal messages. Under HIPAA, a provider must act within 30 days, with one 30-day extension if it explains the delay in writing, and can charge only a reasonable, cost-based fee (45 CFR 164.524). In Michigan, sign and date the request; the provider has 30 days, or 60 if the records aren't kept on-site, plus one 30-day extension with a written explanation (MCL 333.26265).

Can a family sue if a missed diagnosis led to a death?

Yes, through a wrongful death claim brought by the estate's personal representative (MCL 600.2922). In Michigan, the deadline is usually the two years the person would have had, but if they died before it ran out, or within 30 days after, the personal representative may sue within two years after the first letters of authority are issued, and no later than three years after the original deadline (MCL 600.5852). In Ernest v Brown (July 29, 2026), the Michigan Supreme Court held that a notice of intent can pause that extra time too.

Sources

Improving Diagnosis in Health Care (2015): Summary · National Academies of Sciences, Engineering, and Medicine
Improving Diagnosis in Health Care (2015): Chapter 2, The Diagnostic Process · National Academies of Sciences, Engineering, and Medicine
Diagnostic Errors (Patient Safety Primer, last reviewed 2024) · Agency for Healthcare Research and Quality, Patient Safety Network
Never Events (Patient Safety Primer, September 15, 2024), including the National Quality Forum's list of serious reportable events · Agency for Healthcare Research and Quality, Patient Safety Network
Aortic dissection (Medical Encyclopedia) · MedlinePlus, U.S. National Library of Medicine
Newman-Toker DE and others, Serious misdiagnosis-related harms in malpractice claims: The 'Big Three' – vascular events, infections, and cancers, Diagnosis 2019;6(3):227-240 · Diagnosis (abstract via PubMed, National Library of Medicine)
Newman-Toker DE and others, Burden of serious harms from diagnostic error in the USA, BMJ Quality & Safety 2024;33(2):109-120 (author manuscript) · BMJ Quality & Safety (via PubMed Central, National Library of Medicine)
Singh H, Meyer AN, Thomas EJ, The frequency of diagnostic errors in outpatient care: estimations from three large observational studies involving US adult populations, BMJ Quality & Safety 2014;23(9):727-731 · BMJ Quality & Safety (abstract via PubMed, National Library of Medicine)
Malpractice (Wex legal dictionary) · Legal Information Institute, Cornell Law School
Standard of care (Wex legal dictionary) · Legal Information Institute, Cornell Law School
Expert witness (Wex legal dictionary) · Legal Information Institute, Cornell Law School
Michigan Model Civil Jury Instructions: M Civ JI 30.01, 30.03, 30.04 and 30.20 (updated July 21, 2026) · Michigan Supreme Court, Committee on Model Civil Jury Instructions
MCL 600.2912a, Malpractice; burden of proof; loss of opportunity · Michigan Legislature
Matsuyama v Birnbaum, 452 Mass 1 (decided July 23, 2008) · Massachusetts Supreme Judicial Court, via the Caselaw Access Project (Harvard Law School Library)
O'Neal v St John Hospital & Medical Center, 487 Mich 485 (decided July 31, 2010) · Michigan Supreme Court, via the Caselaw Access Project (Harvard Law School Library)
Stone v Williamson, 482 Mich 144 (decided July 24, 2008) · Michigan Supreme Court, via the Caselaw Access Project (Harvard Law School Library)
45 CFR 164.524, Access of individuals to protected health information · Electronic Code of Federal Regulations
45 CFR 164.501, Definitions (designated record set) · Electronic Code of Federal Regulations
MCL 333.26263, Medical Records Access Act: definitions (authorized representative) · Michigan Legislature
MCL 333.26265, Medical Records Access Act: requests for records and response time · Michigan Legislature
MCL 600.2912b, Notice of intent to file a medical malpractice claim; response; records · Michigan Legislature
MCL 600.2912d, Affidavit of merit · Michigan Legislature
MCL 600.2169, Qualifications of expert witnesses in malpractice actions · Michigan Legislature
MCL 600.5805, Injuries to persons or property; period of limitations · Michigan Legislature
MCL 600.5838a, Medical malpractice; accrual, discovery rule and six-year limit · Michigan Legislature
Solowy v Oakwood Hospital Corp, 454 Mich 214 (decided April 29, 1997) · Michigan Supreme Court, via the Caselaw Access Project (Harvard Law School Library)
Bowman v St John Hospital & Medical Center, Docket Nos. 160291 and 160292 (decided July 30, 2021) · Michigan Supreme Court
MCL 600.5851, Claims by minors; children's malpractice claims · Michigan Legislature
MCL 600.5856, Tolling of statute of limitations or repose · Michigan Legislature
MCL 600.1483, Medical malpractice; limitation on noneconomic damages · Michigan Legislature
Limitation on Noneconomic Damages and Product Liability Determination on Economic Damages (January 30, 2026) · Michigan Department of Treasury
MCL 600.6304, Allocation of fault; reduction to the malpractice cap · Michigan Legislature
MCL 600.2922, Wrongful death actions · Michigan Legislature
MCL 600.5852, Wrongful death saving provision · Michigan Legislature
Ernest v Brown, Docket No. 168462 (decided July 29, 2026) · Michigan Supreme Court

Updated September 28, 2026

This guide is general information, not legal advice, and laws change. For advice about your situation, talk to a lawyer licensed in your state. Reading this page or contacting us does not create an attorney-client relationship.