The prosthetic device benefit

Section 1861(s)(8) of the Act covers prosthetic devices, other than dental, which replace all or part of an internal body organ — including colostomy bags and supplies directly related to colostomy care, and including replacement of such devices. 42 CFR 410.36(a)(2) (opens in a new tab) carries the same words into regulation. Read strictly, that is a narrow test: it asks what organ the device stands in for.

The Benefit Policy Manual states the covered category in a wider form, and this is the version that decides most real cases. Prosthetic devices which replace all or part of an internal body organ — including contiguous tissue — or replace all or part of the function of a permanently inoperative or malfunctioning internal body organ are covered when furnished on a physician's order. The function limb is what lets a device that resembles nothing anatomical qualify, and it is why the manual's own examples run from artificial limbs and cardiac pacemakers to breast prostheses after mastectomy, maxillofacial devices, parenteral and enteral nutrition, and devices replacing all or part of the ear or nose.

One phrase in the manual is worth holding onto because it reaches further than it looks: the term "internal body organ" includes the lens of an eye. That is the doorway through which post-cataract eyewear enters a benefit that otherwise buys no spectacles at all, and ophthalmology billing works that case through.

The most common error about this benefit is treating it as the single non-DME bucket. 42 CFR 410.36 (opens in a new tab) — titled medical supplies, appliances and devices — enumerates four families, each with its own test and its own statutory paragraph behind it.

Surgical dressings, splints and casts

Surgical dressings, and splints, casts and other devices used for reduction of fractures and dislocations. Paragraph (a)(1), and section 1861(s)(5) of the Act.

Prosthetic devices

Devices other than dental that replace all or part of an internal body organ, including replacement of the devices themselves and one pair of conventional eyeglasses or contact lenses after each cataract surgery during which an intraocular lens is inserted. Paragraph (a)(2), and section 1861(s)(8).

Braces and artificial limbs

Leg, arm, back and neck braces; artificial legs, arms and eyes; and replacements for them required because of a change in the individual's physical condition. A leg brace may include a shoe where the shoe is an integral part of the brace and its cost is included in the brace's. Paragraph (a)(3), and section 1861(s)(9) — a different paragraph from prosthetic devices, not a subdivision of it.

Lymphedema compression treatment items

Standard and custom fitted gradient compression garments, gradient compression wraps with adjustable straps, compression bandaging systems, and further items determined under 42 CFR 414.1670 — together with accessories such as zippers, liners, and padding or fillers necessary for effective use. Paragraph (a)(4), added to the regulation in November 2023 and the newest of the four.

The braces family has a definition of its own, and it is about mechanics rather than anatomy. The manual describes a brace as a rigid or semi-rigid device used to support a weak or deformed body member, or to restrict or eliminate motion in a diseased or injured part of the body — and says in terms that elastic stockings, garter belts and similar devices do not come within the scope of that definition. Back braces include special corsets such as sacroiliac, sacrolumbar and dorsolumbar corsets and belts. Stump stockings and harnesses are covered where they are essential to the effective use of an artificial limb.

Alongside its definition of prosthetic and orthotic devices, 42 CFR 414.202 (opens in a new tab) carries a short negative list. It is the most practically useful paragraph in the benefit, because each entry is an item a reasonable person would file in the wrong place.

• Parenteral and enteral nutrients, supplies and equipment — not prosthetic or orthotic devices for the purposes of that subpart, even though the Benefit Policy Manual covers parenteral and enteral nutrition on the prosthetic device benefit. The definition and the coverage instruction are answering different questions.
• Intraocular lenses — the implanted lens itself, distinct from the conventional eyeglasses or contact lenses the benefit buys once after the surgery that inserts it.
• Catheters, catheter supplies, ostomy bags and ostomy-care supplies furnished by a home health agency as part of home health services under 42 CFR 409.40(e). The same physical item is inside the benefit when a supplier furnishes it and outside when a home health agency furnishes it under the home health benefit.
• Dental prostheses — dentures are excluded, though the manual covers a denture or part of one where it is a built-in, integral part of an otherwise covered prosthesis, such as an obturator filling an opening in the palate.

It is natural to assume that establishing a benefit category settles how the item is paid. It does not, and the manual works through three cases where the two come apart.

1. 01

   Hemodialysis equipment

   Covered as a prosthetic device — it replaces the function of a kidney — and the manual also records that it meets the definition of DME. Payment for rental or purchase of the equipment in the home is made only under the payment provisions applicable to durable medical equipment.
2. 02

   Parenteral and enteral nutrition

   Coverage of the enteral and parenteral nutritional therapy systems is provided on the basis of the prosthetic device benefit, while the payment rules relating to lump sum or monthly payment for DME apply to the items. The manual notes in passing that some of the accessories — a food pump, an intravenous pole — qualify as DME in their own right.
3. 03

   Therapeutic shoes for people with diabetes

   Neither DME nor orthotics, but a separate category of coverage under Part B at sections 1861(s)(12) and 1833(o) of the Act — and claims for them are nonetheless processed by the DME MACs. A benefit can have its own statutory paragraph and still share a contractor with everything around it.

The practical reading is that "which benefit" and "which payment rules" are two lookups, not one. Getting the first right tells you which coverage test the documentation has to satisfy; it does not tell you whether the item is bought outright, rented, or paid monthly.

Supplies necessary for the effective use of a prosthetic device are covered — the manual's example is the batteries that operate an artificial larynx — and adjustments required by wear or by a change in the patient's condition are covered when a physician orders them. The general provisions for repair and replacement of durable medical equipment are applied to prosthetic devices as well.

Replacement of an artificial limb has its own statutory rule, and it displaced an older one. Section 1834(h)(1)(G)(i) of the Act — added by the Benefits Improvement and Protection Act of 2000 — requires payment for the replacement of prosthetic devices which are artificial limbs, or any part of such a device, without regard to continuous use or useful lifetime restrictions, where an ordering physician determines the replacement is necessary because of a change in the patient's physiological condition, an irreparable change in the condition of the device or a part, or because repairs would cost more than sixty percent of the cost of a replacement device or part. Clause (ii) makes the physician's determination controlling and deems the replacement reasonable and necessary — except that where the device or part being replaced is less than three years old, calculated from the date the beneficiary began using it, the Secretary may also require confirmation that the replacement is necessary. The Benefit Policy Manual records that this provision supersedes any earlier rule providing a five-year or other fixed replacement interval, which is worth knowing because the superseded version still circulates.

One timing rule sits outside all of this and is easy to trip: Medicare does not cover a prosthetic device dispensed to a patient before the procedure that makes the device necessary. Urology billing sets out what that means at the counter, with the manual's own examples of an intraocular lens or a pacemaker handed over at a pre-operative visit.