Although we do not plan to get a Power Assist or Manual Assist  here is some information copied from websites of those available.

The Healthcare Common Procedure Coding System (HCPCS) E0986 is what the Durable Medical Equipment (DME) supplier will input into the system to get a power assist covered by Medicare. You will need to meet the critera for “A push-rim activated power assist device for a manual wheelchair”.

Power Assist

Decon E-Move

Roll easier with less effort. Both drive wheels have two handy and reliable battery-powered motors that sit in the wheel hub. Operate the wheelchair just as you would normally. The difference is you don’t need as much effort to achieve the same result. The two motors work together to keep the wheelchair moving in a straight line. Compatible with the majority of wheelchair models.

E-drive is equipped with quick release axles in order to make it quick and easy to disassemble. The battery hangs either under the seat or on the backrest. It weighs just 2.5 kg, which makes it possible to carry a reserve battery for extra peace of mind. Changing the battery is easy. According to ISO 7176-4, one battery will last a distance of 15 km. A new battery with a 40-km capacity (approx.) is now available.

Alber Twion Electric Drive

The twion is the fastest and lightest push-rim drive in a modern design featuring smartphone connectivity.

The active drive offers new freedom for wheelchair drivers. The compact and silent wheel hub drives with built-in lithium ion batteries ensure greater propulsion force on push-rim wheels.

Moreover, the twion drive wheels are suitable for almost all common active wheelchairs. This is made possible by the small, lightweight bracket that is simply fitted to the wheelchair. With the convenient quick-release system, both the manual wheels and twion drive wheels can be used, meaning that the required drive type, manual or with E Power, is available at all times.

Alber e-Motion

• Electrical wheel hub supports the propelling movement
• Pushing and braking is realised as usual with the push rims
• Gradients and longer stretches are mastered with minimal power expenditure
• Individual driving-characteristic programming options
• Keep active: muscles and joints are relieved of stress while the body is trained
• Suitable for the majority of manual wheelchairs

Yamaha JWX-2

Here is an article about it: Yamaha’s Next-Generation Power-Assist Readies for U.S. Debut

This is what is on their website if you can read Japanese: http://www.yamaha-motor.co.jp/wheelchair/lineup/jwx2/

This is a video from February 2014:

http://www.youtube.com/watch?feature=player_embedded&v=1AVCh5qZNhU

This is a video from 2012:

Quickie (Yamaha) Xtender

The Quickie Xtender expands the range of mobility for manual wheelchair users by adding power assisted wheels to a manual frame.   The Xtender increases your travel distance and propulsion efficiency and reduces overall fatigue while allowing you to maintain the look, control, and functionality of a manual wheelchair.

Manual Assist

NuDrive

NuDrive is the innovative new lever-drive propulsion accessory for manual wheelchairs, providing more mobility and improving physical well-being.

With NuDrive you don’t need to propel your chair by gripping the wheel rims by hand; instead, you can propel yourself forwards, backwards, manoeuvre and brake, simply by pushing the levers.

Rio Mobility Pivot

Benefit from the natural propulsion of a lever drive and amplify your effort. Go fast on the flats or climb hills with ease with 5 speeds to choose from!

Use both the push and pull stroke for more power and balanced muscle development. Reduce shoulder and wrist pain, fatigue, and injuries. Rediscover your neighborhood!

No need to grip the push rim, keep your hands clean! Reduce carpal tunnel symptoms and everyday wear and tear. Please consult your healthcare professional to verify the equipment is appropriate for your medical condition.

Wijit

The Wijit a wheel with a lever drive, gears, and brakes that replaces the wheels on a manual wheelchair. It can be installed on most manual wheelchairs. The Wijit has superior ergonomics compared to a conventional push-rim wheelchair. With the Wijit you can easily and safely drive, steer and stop your chair from a comfortable, upright position.

The combination of the lever drive and the transmission reduces the force required to move your chair. And reduces the number of times you have to push the wheels each day by a factor of 2 to 3. The brakes let you stop the chair easily. Quick release hubs make it easy to remove and install the wheels to simplify transporting your chair. The Wijit lets you drive, steer and brake without ever touching the wheels!

MagicWheels

MagicWheels are wheelchair wheels with a geared hub that provides a 2:1 mechanical advantage and an automatic hill-holder. They are great for climbing hills, ramps, curb cuts, or door thresholds. Unlike power assist wheels, MagicWheels 2-gear wheelchair wheels have no batteries and no motors. You only use the geared technology when you need it, engaging it with a simple click of the hub. The remainder of the time your wheelchair works similarly to how it does with conventional wheelchair wheels installed.