CMS Pub. 100-03, ch. 1, § 230.7

Dialysis

(Rev. 173, Issued: 09-04-14, Effective: Upon Implementation: of ICD-10, Implementation: Upon Implementation of ICD-10)

A. Water Purification Systems

Water used for home dialysis should be chemically free of heavy trace metals and/or organic contaminants

that could be hazardous to the patient. It should also be as free of bacteria as possible but need not be

biologically sterile. Since the characteristics of natural water supplies in most areas of the country are such

that some type of water purification system is needed, such a system used in conjunction with a home

dialysis (either peritoneal or hemodialysis) unit is covered under Medicare.

There are two types of water purification systems that will satisfy these requirements:

• Deionization - The removal of organic substances, mineral salts of magnesium and calcium (causing

hardness), compounds of fluoride and chloride from tap water using the process of filtration and ion

exchange; or

• Reverse Osmosis (RO) - The process used to remove impurities from tap water utilizing pressure to

force water through a porous membrane.

Use of both a deionization unit and RO unit in series, theoretically to provide the advantages of both

systems, has been determined medically unnecessary since either system can provide water which is both

chemically and bacteriologically pure enough for acceptable use in home dialysis. In addition, spare

deionization tanks are not covered since they are essentially a precautionary supply rather than a current

requirement for treatment of the patient.

Activated carbon filters used as a component of water purification systems to remove unsafe concentrations

of chlorine and chloramines are covered when prescribed by a physician.

B. Water Softening System

Except as indicated below, a water softening system used in conjunction with home dialysis is excluded

from coverage under Medicare as not being reasonable and necessary within the meaning of §1862(a)(1) of

the Social Security Act. Such a system, in conjunction with a home dialysis unit, does not adequately

remove the hazardous heavy metal contaminants (such as arsenic) which may be present in trace amounts.

A water softening system may be covered when used to pretreat water to be purified by a RO unit for home

dialysis where:

The manufacturer of the RO unit has set standards for the quality of water entering the RO (e.g., the water to

be purified by the RO must be of a certain quality if the unit is to perform as intended);

The patient’s water is demonstrated to be of a lesser quality than required; and,

The softener is used only to soften water entering the RO unit, and thus, used only for dialysis. (The

softener need not actually be built into the RO unit, but must be an integral part of the dialysis system.)

C. Developing Need When a Water Softening System is Replaced with a Water Purification Unit in an

Existing Home Dialysis System

The medical necessity of water purification units must be carefully developed when they replace water

softening systems in existing home dialysis systems. A purification system may be ordered under these

circumstances for a number of reasons. For example, changes in the medical community’s opinions

regarding the quality of water necessary for safe dialysis may lead the physician to decide the quality of

water previously used should be improved, or the water quality itself may have deteriorated. Patients may

have dialyzed using only an existing water softener previous to Medicare end-stage renal disease coverage

because of inability to pay for a purification system. On the other hand, in some cases, the installation of a

purification system is not medically necessary. Thus, when such a case comes to the A/B MAC (A)’s

attention, the MAC asks the physician to furnish the reason for the changes. Supporting documentation,

such as the suppliers’ recommendations or water analysis, may be required. All such cases should be

reviewed by the MAC’s medical consultants.

Cross reference: - The Medicare Benefit Policy Manual, Chapter 15, “Covered Medical and Other Health

Services,” §110.