Medicare covers a range of equipment after knee replacement surgery, primarily through Part B’s durable medical equipment (DME) benefit. This includes mobility aids like walkers and crutches, and can extend to items like knee braces and raised toilet seats when a doctor certifies they are medically necessary. The specifics of what you receive, how much you pay out of pocket, and which suppliers you can use depend on details that trip up many people during an already stressful recovery period.
What Counts as Durable Medical Equipment
Medicare defines durable medical equipment as items that are primarily medical in nature, can withstand repeated use, serve a medical purpose in your home, and are expected to last at least three years. That definition matters because it draws the line between what Medicare will and won’t pay for after your knee replacement. A standard walker meets every criterion. A set of grip socks to prevent slipping around the house does not, because Medicare considers them comfort or convenience items rather than medical devices.
After a total knee replacement, the most commonly covered DME items include:
- Walkers: Standard and wheeled walkers are routinely covered when prescribed by your surgeon or primary care doctor.
- Crutches: Typically covered for the initial weeks when you need them to move around safely.
- Canes: Covered when your doctor documents that you need one for safe ambulation during recovery.
- Knee braces: Covered when prescribed as medically necessary, though the type of brace and its cost can vary.
- Raised toilet seats: Covered in some circumstances when a physician documents the medical need, though coverage for bathroom safety equipment can be inconsistent.
- Hospital beds: Covered for home use if your doctor certifies you cannot safely use a regular bed due to your medical condition.
Each of these items requires a prescription or order from a treating physician. Medicare will not reimburse equipment you buy on your own without a doctor’s order, even if the item would clearly help your recovery. The prescription is non-negotiable.
How Much You Pay Out of Pocket
Under Original Medicare (Parts A and B), DME falls under Part B. After you meet the annual Part B deductible, Medicare generally pays 80 percent of the Medicare-approved amount for covered equipment. You are responsible for the remaining 20 percent. If you have a Medigap (Medicare Supplement) policy, it may cover part or all of that 20 percent coinsurance, depending on the plan you selected.
The “Medicare-approved amount” is a key concept here. This is the price Medicare has determined is reasonable for a given piece of equipment, not necessarily what the supplier charges. If your supplier accepts Medicare assignment, they agree to accept the Medicare-approved amount as full payment, and your 20 percent is calculated from that approved figure. If the supplier does not accept assignment, they can charge up to 15 percent more than the approved amount, and you are on the hook for the difference plus your coinsurance. For equipment purchases, always confirm that your supplier accepts assignment before placing an order.
Medicare-Approved Suppliers and Why They Matter
Medicare requires that DME be obtained from suppliers enrolled in the Medicare program. You cannot buy a walker from a general retail store, submit the receipt, and expect reimbursement. The supplier must have a Medicare supplier number, and in many parts of the country, DME falls under a competitive bidding program that limits which suppliers can bill Medicare in your area.
Your doctor’s office or the hospital’s discharge planning team will typically provide a list of approved suppliers, or you can search for them through Medicare’s supplier directory. Using a non-enrolled supplier means you bear the full cost yourself. This is one of the most common and avoidable mistakes people make after surgery: buying equipment at a pharmacy or online retailer that is not a Medicare-enrolled DME supplier.
Some items, particularly walkers and crutches, are purchased outright. Others, like hospital beds, may be rented through Medicare, with the rental eventually converting to a purchase after a set number of months. The supplier handles the billing distinction, but you should understand whether you are renting or buying, because it affects your ongoing coinsurance obligations.
The CPM Machine Question
Continuous passive motion (CPM) machines are motorized devices that slowly bend and straighten your knee while you lie in bed. They were once standard equipment after knee replacement, and Medicare historically covered them as DME for home use. Over the past decade, however, the evidence supporting their routine use has weakened considerably. Many orthopedic surgeons no longer prescribe them, favoring active physical therapy exercises instead.
Medicare can still cover a CPM machine if your surgeon prescribes it and documents the medical necessity. But the shift in clinical practice means fewer surgeons write that prescription, and some Medicare Administrative Contractors (the regional entities that process Medicare claims) have tightened their coverage criteria. If your surgeon believes a CPM machine will benefit your recovery, push for clear documentation in your medical record explaining why. Without that documentation, the claim is likely to be denied.
If you are told you need a CPM machine, confirm with the supplier and your Medicare plan before the device is delivered. A denial after the fact can leave you responsible for the full rental cost, which can run to several hundred dollars per week.
Home Health Services and the Equipment That Comes With Them
Medicare Part A covers home health services after knee replacement if you are homebound (meaning leaving home requires considerable effort) and your doctor certifies you need skilled care such as physical therapy or nursing. When home health is approved, the home health agency may bring certain equipment as part of the care plan, and the cost is bundled into the home health benefit rather than billed separately as DME.
This distinction matters because home health services under Part A have no coinsurance for the skilled services themselves. If a physical therapist visits your home and brings a set of resistance bands or portable exercise equipment as part of your therapy sessions, you typically are not billed separately for those items. However, larger DME items like a walker or hospital bed are still billed through Part B even if the home health agency arranges them.
Home health coverage is time-limited and tied to ongoing medical necessity. Once you are no longer homebound or no longer need skilled care, the home health benefit ends. Any equipment you still need at that point continues to be covered under Part B’s DME benefit as long as your doctor continues to certify the need.
What About Wheelchairs and Scooters
Most people recovering from a single knee replacement will not need a wheelchair long-term, but short-term wheelchair use is sometimes necessary, particularly for people with additional mobility limitations or those recovering from bilateral (both knees) surgery. Medicare Part B covers manual wheelchairs when a doctor documents that you need one for use inside your home. Power wheelchairs and scooters have stricter criteria: Medicare generally requires a face-to-face examination, documentation that you cannot perform daily activities without the device, and evidence that a manual wheelchair is insufficient.
For knee replacement patients specifically, wheelchair coverage tends to be temporary. If your surgeon expects you to regain walking ability with rehabilitation, Medicare may approve a short-term wheelchair rental rather than a purchase. The practical takeaway is that if you think you will need a wheelchair during recovery, have that conversation with your surgeon before discharge so the documentation is in place.
Equipment Medicare Typically Does Not Cover
Several items that seem like they should be covered often are not, and this catches people off guard during recovery. Common exclusions include:
- Grab bars: Unless installed as part of a covered home modification (which Original Medicare generally does not cover), grab bars for your bathroom are considered home safety items, not DME.
- Shower chairs or benches: Coverage is inconsistent. Some Medicare plans cover them with a doctor’s prescription; others classify them as convenience items. Check with your specific plan before purchasing.
- Ice therapy machines: Motorized cold therapy units are popular after knee surgery, but Medicare frequently denies them as not medically necessary, considering them equivalent to a simple ice pack.
- Exercise equipment: A stationary bike or pedal exerciser for home rehabilitation is not covered, even if your physical therapist recommends it.
- Compression stockings: Generally not covered under Part B’s DME benefit, though they may be provided during your hospital stay.
The general pattern is that Medicare covers equipment that is clearly medical and necessary for basic function, and tends to exclude items it views as convenience, comfort, or general wellness aids. The lines can feel arbitrary when you are the one recovering, but they are drawn based on longstanding Medicare coverage rules.
Medicare Advantage Plans and Equipment Differences
If you have a Medicare Advantage plan (Part C) rather than Original Medicare, your DME coverage must be at least as generous as Original Medicare’s, but the details can differ in meaningful ways. Medicare Advantage plans often have their own networks of approved DME suppliers, and using an out-of-network supplier can dramatically increase your costs or result in no coverage at all.
Some Medicare Advantage plans offer supplemental benefits that Original Medicare does not, such as coverage for bathroom safety equipment, post-surgical meal delivery, or transportation to physical therapy appointments. These extras vary widely by plan and by region. Before your surgery, call your plan and ask specifically what DME is covered, which suppliers are in network, and whether any prior authorization is required before equipment is ordered. Getting this information in writing is worth the effort, because verbal assurances from a phone representative do not always match what happens when the claim is processed.
Prior authorization is more common in Medicare Advantage than in Original Medicare. Your surgeon’s office may need to submit paperwork justifying the equipment before it is approved. Delays in prior authorization can mean delays in getting your walker or other equipment, so start the process well before your surgery date if possible.
Timing and the Hospital Discharge Process
Most of the equipment you will need immediately after surgery is arranged during discharge planning at the hospital. A case manager or discharge planner typically coordinates with a DME supplier to ensure you have a walker, crutches, or other essential items ready when you go home. If your surgery is outpatient (and many knee replacements now are), this process may be more compressed, with equipment arrangements handled during a pre-surgical visit.
Do not assume the hospital will automatically provide everything you need. Be proactive: ask your surgeon’s office before the procedure what equipment will be ordered, confirm it is being ordered through a Medicare-enrolled supplier, and clarify what your out-of-pocket cost will be. Hospitals sometimes provide equipment from their own stock and bill it as part of the facility charges (covered under Part A if you are an inpatient), but once you leave, any additional equipment is a Part B expense.
If you are discharged to a skilled nursing facility for rehabilitation before going home, the facility covers your DME needs during your stay. Your equipment needs are reassessed before you are discharged home, and any items you need at home are ordered at that point through a DME supplier and billed under Part B.
When Equipment Is Denied and What You Can Do
Medicare denials for DME are not uncommon, and they are not the end of the road. If a claim is denied, you have the right to appeal. The first level of appeal is a redetermination, which is essentially asking Medicare to look at the claim again with any additional documentation your doctor can provide. Many denials happen because the initial paperwork did not sufficiently establish medical necessity, and a letter from your surgeon explaining why you need the equipment can resolve the issue.
If the redetermination is also denied, further levels of appeal exist, including review by an independent contractor and an administrative law judge hearing. The appeal process can be slow, but success rates at higher appeal levels are surprisingly favorable for beneficiaries. In the meantime, if you need the equipment urgently, you may have to pay out of pocket and seek reimbursement if the appeal succeeds.
One practical tip: if your surgeon recommends a piece of equipment that is frequently denied (like a CPM machine or a power wheelchair), ask the surgeon’s office to use specific clinical language in the prescription and supporting documents that directly addresses Medicare’s coverage criteria. The office staff who handle DME orders regularly usually know what language Medicare reviewers look for.