If you have a bacterial infection, you need to take antibiotics. If health care providers need to determine that you have a broken bone, you’ll need to have an X-ray.
Those are some examples of medical care that’s considered medically necessary, but other procedures, medications and services may be more ambiguous as to whether they’re considered medically necessary.
It’s important to understand what types of care are generally considered necessary, since it’s a term used by insurance companies, including Medicare, to determine coverage.
[READ The Best Medicare Advantage Plans]
What Is Medical Necessity?
You may hear insurance companies use the term “medical necessity” when talking about services covered by your plan.
“(Medical necessity) refers to care that is reasonable, appropriate and essential for your health,” says Dr. Saamer Siddiqi, a Chicago-based board-certified internal medicine hospitalist and founder and CEO of LIVEMED, a company that supports rural and community hospitals. “It’s the kind of treatment a doctor determines is needed to diagnose, treat or prevent a serious condition, rather than something done for convenience, preference or cosmetic reasons.”
Whether a procedure is medically necessary may also depend on the standard of practice for health care practices in your area, as well as any state laws governing medical necessity.
[READ 6 Most Expensive Medical Procedures, Ranked]
Why Does Medical Necessity Matter for Medicare Coverage?
If you have Medicare or private health insurance, it’s important to understand the idea of medical necessity as it can determine what your health care plan will cover or not cover. Each health insurance policy will define medical necessity and their standards and procedures within the policy. How they define medical necessity will impact which procedures they cover.
When you’re part of a health plan like Medicare, “medical necessity matters because claims submitted for services that do not meet the criteria of medical necessity are typically denied, meaning the full cost is passed on to the patient,” says Whitney Stidom, vice president of consumer enablement at eHealth, an online health insurance marketplace.
The definition of medical necessity will depend on national coverage decisions regarding Medicare as well as your state laws. Nationally, the Centers for Medicare and Medicaid Services (CMS) uses data and research to make national coverage determinations (NCDs), which determine whether or not a procedure is covered by original Medicare. When a procedure does not fall under a NCD, it’s up to the Medicare contractors to make a local coverage determination (LCD).
Does medical necessity apply to Medicare Advantage plans?
Medicare Advantage plans can set their own standards for what is medically necessary, but they must cover, at a minimum, the same health services that original Medicare covers. They may also set their own requirements for prior authorization, which may mean that the plan has to approve your services before you receive them.
What about medical necessity for Medicaid?
Since states are responsible for administering Medicaid, each state has a definition of “medical necessity” outlined for their Medicaid programs. You can find your state’s definition of what is “medically necessary” for Medicaid within the state Medicaid policy.
[READ: Medicare vs. Medicaid: Key Differences, Eligibility & Coverage]
Which Procedures and Medications Are Medically Necessary?
The best way to find out if medical treatments that you need are considered medically necessary is by reading the policy documents, says Barbara Hopkins, a licensed insurance agent and Medicare consultant based in South Portland, Maine. Although they may be hard to follow, they’re an important part of understanding your coverage.
Some examples of care that are typically considered medically necessary include:
— Anesthesia for many types of surgery
— Antibiotics for an infection
— Cardiac rehabilitation
— Mammogram screening to detect breast cancer
— Oxygen when you can’t breathe
— X-rays to determine if you have a broken bone
Procedures and Medications Often Deemed “Not Medically Necessary”
Health services that may not meet the definition of medical necessity and therefore may not be covered by Medicare include:
— Cosmetic procedures (the type of procedures you’re having just to look better)
— Experimental surgeries
— Medications prescribed for off-label uses, or that are prescribed for a condition that the drug was not originally approved for
— Tests that are not specifically related to the health problem that you have or may have
Keep in mind that there are other types of health needs that Medicare Parts A and B do not cover. They may be medically important, but they are covered within different types of Medicare coverage, like Medicare Advantage (also called Part C) plans, Hopkins says. These include:
— Eye exams for prescription glasses
— Hearing aids and the exams to fit them
If you’re unsure if a medication, test or treatment is necessary for your health problem, just ask your provider, “Is this really necessary for me, or is it extra?” Simply asking the question can help you assess if something is valuable for your time and may help you avoid an unexpected bill.
Documentation for Medical Necessity
Sometimes, Medicare coverage or other health insurance plans will want a Certificate of Medical Necessity from a health care provider to demonstrate that a certain service (like home health care), treatment or medication is medically necessary. Provider offices are usually familiar with this process and will often know what types of treatments may trigger the need for a Certificate of Medical Necessity.
It also can be useful to work with your health provider’s office to determine if prior authorization is needed for a test, treatment or service. This involves getting prior approval for a medication or treatment to ensure that it will be covered by your plan.
“Because if there’s any doubt, filing a pre-authorization request with the insurer can save them a lot of worry and hassle, and potentially a lot of money, too,” Stidom says.
Each insurance plan, be it for Medicare or non-Medicare plans, will have a prior authorization process. Often, a provider will write a letter to explain a person’s condition and why the specific treatment should be approved. The provider also may send lab results or medical records to further support the care they are recommending.
It may take up to a few weeks to hear if a prior authorization request is approved, Stidom says.
What to Do If Your Medicare Claim Is Denied
If your Medicare claim or prior authorization for a specific medication, service or treatment is denied, take a deep breath. “It’s not a horrible, scary thing if you’re denied,” Hopkins says.
A 2025 Health Affairs study found that 17% of claims through Medicare Advantage were denied, but 57% of those were ultimately overturned.
“Most people stop too early, but a lot of denials get overturned once the details are laid out,” Siddiqi says. “An appeal gives you a chance to add missing records, provider letters or other evidence that shows why the care is necessary.”
“A strong, well-written letter can open the door where a simple claim might have been turned away,” Siddiqi adds.
Work with your health provider to file an appeal if a claim is denied. Your provider’s office can give more details in writing about why you need a certain type of treatment and share more background about your medical situation.
Find the Best Medicare Advantage and Medicare Part D Plans With U.S. News
Start your search for the right plan for you with U.S. News’ Best Medicare Advantage Plans and Best Medicare Part D Companies. You can also look for and compare Medicare Advantage, Medicare Part D, bundled Medicare Advantage and Part D plans and Medicare supplement plans near you with the U.S. News search and compare tool.
To determine the top-rated insurance companies, U.S. News consulted with Medicare experts to identify and weigh the most important quality measures for Medicare Advantage consumers, applied these weights to data from the Centers for Medicare & Medicaid Services and then adjusted for enrollment.
More from U.S. News
What to Pack in Your Hospital Bag Before a Surgery or Procedure: A Checklist
Migraine Hacks and Remedies for Fast Relief
13 Health Superstitions to Reconsider
Medical Necessity for Medicare: Certificates and Tips originally appeared on usnews.com
