Millions of seniors on Medicare are getting a one-time $90 payment this month. On Thursday, President Trump sent many of them an email about it.

"You are receiving a One-Time Payment of $90 to offset some of the cost of your October Medicare premium," the email said, The Washington Post reported. It said the move would make sure "these funds benefit YOU." The email also praised his policies.

Trump announced the payments on Oct. 2. In a late-night post, he promised checks "of nearly $100," Newsweek reported. The amount turned out to be $90.

More than 20 million people are eligible, Fox Business reported. Most get the money by direct deposit on or around Oct. 8. Others will get a paper check from the Treasury later in October.

The money comes from the Medicare Improvement Fund. Congress created it in 2008 to pay for improvements to traditional Medicare. This is the first time it has been used to send money straight to people. The White House says Congress put $2 billion into the fund, according to Fox Business.

Trump called the fund a "pointless 'Slush Fund'" used by Democrats, Newsweek reported. The Post reported that Trump was taking money Congress set aside to improve Medicare, and Democrats and senior advocates called the payments a stunt.

The payment will not go far. The standard Part B premium is $202.90 a month in 2026, up from $185. So the $90 covers about 44% of one month, Fox Business reported. It is not a recurring payment. The health research group KFF said fewer than half of Medicare enrollees would get it, Newsweek reported.

Not everyone qualifies. People in Medicare Advantage plans are left out. So are people whose premiums Medicaid pays and higher earners who pay an extra income-based charge.

Seniors can call 1-800-MEDICARE (1-800-633-4227) to check whether they qualify. They can call Social Security at 1-800-772-1213 to ask about a payment's status.

The payments land just weeks before the midterm elections.

What we know: Eligible seniors get one $90 payment this month from a fund meant to improve Medicare.
What we don't: Whether the payment will sway any voters before the midterms.