Hundreds of thousands of Californians will soon receive their last unemployment check unless and until Congress extends federal benefits.

Those most at risk of losing benefits immediately are people who are at or nearing the end of either their regular state benefits or one of four federal extensions. In addition, people who are receiving what California calls Fed-Ed, the very last round of benefits, could lose them immediately no matter where they are in that process.

A test vote in the Senate on a bill to extend benefits failed Wednesday. The bill included a host of other tax and spending measures that would add $85 billion to the deficit over 10 years. Lawmakers are considering ways to scale back the measure, perhaps by eliminating the extra $25 per week in unemployment benefits authorized in last year's economic stimulus act.

In California, people who are eligible for unemployment benefits receive up to 26 weeks of regular state benefits.

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Until federal funding ran out, people who exhausted their regular state benefits and were still eligible for unemployment could receive four consecutive rounds of federal extended benefits: The first tier was up to 20 weeks, the second up to 14, the third up to 13 and the fourth up to six.

When the fourth ran out, they could move on to a final round of benefits with special rules known as Fed-Ed, for up to 20 weeks.

That's a grand total of 99 weeks of unemployment.

Federal funding for all four tiers of extended benefits and Fed-Ed ran out at the end of May.

Most people thought Congress would extend funding before people starting missing checks, as it has done several times since the recession began. But with concern over the deficit mounting, that is becoming harder to do.

The California Employment Development Department has begun notifying some people that their benefits could be interrupted or terminated. If Congress does nothing:

-- People who are receiving regular state benefits (up to 26 weeks) will continue receiving them until they run out, but will get nothing further.

-- People who are receiving one of the four tiers of federal extended benefits will continue receiving that tier until it is exhausted, but can not move on to the next tier or to Fed-Ed.

-- People who are receiving Fed-Ed will receive no more checks, no matter where they are in that round. The week ending June 12 was the last payable week for these benefits. As of Monday, almost 100,000 Californians were receiving these benefits, EDD says.

-- Any new claims filed after May 30 will not include the additional $25 per week stimulus payments. People already receiving the extra $25 per week payment will continue to get it until they exhaust whatever round of benefits they are receiving, but not thereafter.

At the end of May, the House passed H.R. 4213, the American Jobs and Closing Tax Loopholes Act, which would extend federal funding for extended unemployment benefits and the $25 weekly bonus through the end of November.

The Senate has not yet voted on its version of the bill, which also would extend benefits through the end of November. On Wednesday, a procedural vote to move forward on the bill failed to get the necessary 60 votes.

EDD is maintaining a list of people who have just run out of their regular benefits or extended benefits. "In the event extension filing deadlines are eventually extended, EDD will automatically file further extension claims for these customers and notify them of the additional benefits for which they might then qualify," it says in a press release, which you can find at links.sfgate.com/ZJVW.

It's possible that Congress could extend benefits retroactively to compensate those who had a gap in payments, says EDD spokeswoman Loree Levy. "That's why we're keeping the list," which already includes an additional 100,000 people.

However, there is no discussion in Congress about extending benefits beyond the maximum of 99 weeks. (The maximum is less than 99 weeks in some states with lower unemployment rates.)

On a related note, neither the House nor the Senate version of the bill would extend the federal subsidy for Cobra health insurance premiums. Eligibility for the subsidy also expired at the end of May. People who are receiving the subsidy can keep getting it until they have received it for 15 months. But people who are laid off after May 31 are ineligible to receive the subsidy.

Last week, Sens. Bob Casey, D-Pa., and Sherrod Brown, D-Ohio, introduced an amendment that would extend eligibility for the Cobra subsidy through Nov. 30, but "that has not been voted on yet and rumors are, even if voted on, it would not pass," says Mark Luscombe, principal tax analyst with CCH.