It appears there is no code for this. I found a relevant document on the cms.gov site:
http://www.cms.gov/Medicare/Coding/MedHCPCSGenInfo/Downloads/050912-Agenda-Supply-Other.pdf
The above document is from May 9 2012. A manufacturer of walk-in bath tubs was requesting code for these types of tubs. The following is part of the document.
"Background/Discussion:
According to the requester, Safety Tub Walk-in baths are bath fixtures with inward opening
doors to allow ease of entry and exit. Safety Tub utilizes a patented, watertight door system with
a self-sealing gasket and is supported by a freestanding metal support frame with leveling feet.
These walk-in bath fixtures include an integrated 17" high seat, integrated grab bars, and cable
driven drains. Safety Tub is available as a soaker unit without hydromassage or with a variety of
hydromassage systems including whirlpool, heated air injection, or combination system. All
products are available in either a left or right handed drain version. According to the requester,
there are no existing codes to describe accessible bathing fixtures.
Preliminary Decision:
A national program operating need to establish a code for this product was not identified by
Medicare, Medicaid or the Private Insurance Sector. For coding guidance, contact the entity in
whose jurisdiction a claim would be filed. For Medicaid, contact the Medicaid Agency in the
state in which a claim would be filed. For private insurance, contact the individual insurance
contractor. For Medicare, contact the Medicare contractor.
Medicare Payment:
Based on our preliminary benefit category analysis, we believe that there would be no Medicare
payment for this item."