Why Medicare advantage plans want to send a doctor to your house

I recently received a phone message from someone calling "on behalf of my Medicare advantage plan provider," offering to have a medical person visit me in my home.  I knew the plan had offered such, but wasn't clear why.  Is their intention for our mutual benefit (to keep me healthy and lower their costs) or is it something more sinister?  A web search yielded all sorts of speculation on message boards ("they'll find something wrong and cut you off" "they'll spy on your home for excuses to discontinue your coverage" etc).

Today I found at The Center for Public Integrity what seems to be the most logical explanation:

Home visits have risen sharply at many private Medicare health plans, which treat close to 16 million elderly and disabled people under contracts with the federal government.

The health plans tout the voluntary, free annual physicals as a major new benefit that can help selected members stay fit and in their homes as long as possible. While the doctors and nurses don’t offer any treatment during their visit, they report their exam findings to the patient’s primary care physician.

Yet there’s more to this spurt in home visits than the appearance of enhanced elder care. The house calls can be money makers for health plans when they help document medical problems — from complications of diabetes to a history of heart trouble that’s flared up.

Health plans can profit because Medicare pays them higher rates for sicker patients using a billing formula known as a “risk score.” So when a home visit unearths a medical condition, as it often does, health plans may be able to raise a person’s risk score and collect thousands of dollars in added Medicare revenue over a year — even if they don’t incur any added expenses caring for that person...

The cottage industry is flourishing as federal officials struggle to prevent Medicare Advantage plans from overcharging the government by billions of dollars every year...

Lots more at the link.