WASHINGTON (AP) - Sure, $4 trillion sounds like a lot.

WASHINGTON (AP) — Sure, $4 trillion sounds like a lot.

But it goes fast when your budget stretches from aging highways to medical care to space travel and more.

Here's an agency-by-agency look at how President Barack Obama would spend Americans' money in the 2016 budget year beginning Oct. 1:

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AGRICULTURE

Up or down? Up 3 percent

What's new? A new food safety agency.

Highlights:

—The budget proposes consolidating the Agriculture Department's Food Safety and Inspection Service with the Food and Drug Administration's food safety oversight in a new agency under the Health and Human Services Department. If Congress goes along with the proposal, USDA would lose one of its main functions.

— As in years past, the administration is proposing to cut money for farmers' crop insurance to pay for other agriculture programs. This year's budget proposes about a $1.6 billion annual cut in the program, which subsidizes both the companies that sell crop insurance and farmer premiums. The program was estimated to cost more than $9 billion last year, and the Obama administration says in its budget that "overly generous benefits have almost eliminated the risk in farming at a cost to taxpayers in the billions." The budget says the cuts are intended to slim the program while keeping a safety net for farmers. There will be little appetite for that reform in Congress, however, where funding for crop insurance has been a priority. The five-year farm bill Obama signed into law last year increases spending for crop insurance.

— The bulk of the USDA budget is nutrition programs. Food stamps alone are estimated to cost $83.7 billion for the 2016 budget year. Though fewer people are expected to apply for food stamps in the coming years, food prices are expected to keep the cost higher.

The numbers:

Total spending: $156 billion, including spending on farm subsidies and nutrition programs already required by law.

Spending that needs Congress' annual approval: $24.4 billion

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COMMERCE

Up or down? Down 12.8 percent

What's new? A fund for new technology companies.

Highlights:

—Obama's Commerce Department budget proposes a new Scale-Up Fund, designed to help new startup companies develop technologies that can be manufactured in the U.S.

—Obama would expand a network of manufacturing institutes around the country from nine to 45. The institutes are designed to coordinate the federal government's work with local companies and schools to develop technologies that the U.S. can produce.

—Spending for the Census Bureau ramps up slightly as the agency prepares for its once-every-decade count of America's population.

The numbers:

Total spending: $12.4 billion. While programs approved annually by Congress would grow by 11 percent, other Commerce spending shows a decline, including funds that get money from the Federal Communications Commission's sales of space on the electronic spectrum.

Spending that needs Congress' annual approval: $9.8 billion

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EDUCATION

Up or down? Down 24.3 percent.

What's new? A proposal for free community college.

Highlights:

—Obama wants to make two years of community college free and as easy to access as high school. To do so, he would give grants to states that agree to make tuition free to students who meet certain conditions, if those states contribute to the effort and seek to improve the quality of their community colleges. The budget seeks $1.4 billion for the effort. Overall, the program is estimated to cost $60 billion over 10 years. The proposal has received a cold reception from many Republicans on Capitol Hill, however.

—Obama has long emphasized expanding and improving early education programs, including using an increase in tobacco taxes to make preschool available to all 4-year-olds. The budget seeks $750 million for preschool development grants to states to expand access and improve quality of early education programs, meant to lay the groundwork for universal pre-K. Such a grant program is already assisting 18 states with the effort, but the budget seeks $500 million more than was enacted in the 2015 budget. Obama also seeks $1.5 billion in new spending by the Health and Human Services Department for Head Start programs — money that would help make Head Start available for a full day and all year for some children and expand services for expecting parents and very young children. Congressional Republicans, however, have pushed to improve existing federally funded early childhood programs before dramatically expanding them.

— The budget would provide a $1 billion increase in Title 1 funding, meant to close inequities in education.

The numbers:

Total spending: $73.8 billion

Spending that needs Congress' annual approval: $70.8 billion.

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ENVIRONMENTAL PROTECTION AGENCY

Up or down? Up 56 percent

What's new? A $4 billion fund for use by states that cut the pollution blamed for global warming from power plants deeper and faster than required.

Highlights:

— After cutting the Environmental Protection Agency's budget for years, Obama is proposing the largest increase to the agency's budget of his presidency, as he doubles down on plans to curb the pollution blamed for global warming. But look for Republicans, now in control of Congress, to whack the EPA budget.

— Obama's proposal includes $239 million for the EPA to address climate change, including the marquee rules due this summer to cut heat-trapping pollution from new and existing power plants. About $25 million is set aside for states to help them draft plans to meet the power plant rules. Numerous states have already sued the agency over its plans, and have complained that meeting the proposal will be complicated and burdensome.

— For the first time, the EPA budget establishes a $4 billion fund for use by states that cut pollution blamed for global warming at power plants deeper or faster than required. But that proposal would require Congress to find an offset to pay for it. That's unlikely with congressional Republicans aiming to dismantle the EPA's climate efforts.

— With several chemical, coal and oil spills tainting water supplies recently, Obama's budget also includes $50 million for the EPA to help assist states, tribes and private companies to upgrade drinking water and sewer systems. The budget also calls for $2.3 billion in low-interest loans and grants to communities to make improvements in drinking water and sewage treatment and infrastructure.

The numbers:

Total spending: $12.5 billion

Spending that needs Congress' annual approval: $8.6 billion, but that doesn't include the new $4 billion proposed.

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HEALTH AND HUMAN SERVICES

Up or down? Up 4.3 percent

What's new? Medicare could negotiate prices for cutting-edge drugs.

Highlights:

— The president's proposed health care budget asks Congress to authorize Medicare to negotiate what it pays for high-cost prescription drugs and for biologics, including advanced medications for diseases such as rheumatoid arthritis. Currently, private insurers bargain on behalf of Medicare beneficiaries. Drug makers have beaten back prior proposals to give Medicare direct pricing power. But the introduction of a $1,000-a-pill hepatitis-C drug last year may have shifted the debate.

— Tobacco taxes would nearly double, to extend health insurance for low-income children. The federal cigarette tax would rise from just under $1.01 per pack to about $1.95 per pack. Taxes on other tobacco products also would go up. That would provide financing to pay for the Children's Health Insurance Program through 2019. The federal-state program serves about 8 million children, and funding technically expires Sept. 30. The tobacco tax hike would take effect in 2016.

— Starting in 2019, the proposal increases Medicare premiums for high-income beneficiaries and adds charges for new enrollees. The charges for new enrollees include a home health copayment, changes to the Part B deductible, and a premium surcharge for seniors who've also purchased a kind of supplemental insurance whose generous benefits are seen as encouraging overuse of Medicare services.

— There's full funding for ongoing implementation of Obama's health care law.

—The plan would end the budget sequester's 2 percent cut in Medicare payments to service providers and repeal another budget formula that otherwise will result in sharply lower payments for doctors. But what one hand gives, the other hand takes away. The budget also calls for Medicare cuts to hospitals, insurers, drug companies and other service providers.

The numbers:

Total spending: $1.1 trillion, including about $1 trillion on benefit programs including Medicare and Medicaid, already required by law.

Spending that needs Congress' annual approval: $80 billion.

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NASA

Up or down? Up 2.9 percent

What's new? Not much. Just more money for planned missions.

Highlights:

—The exploration budget — which includes NASA's plans to grab either an asteroid or a chunk of an asteroid and haul it closer to Earth for exploration by astronauts — gets a slight bump in funding. But the details within the overall exploration proposal are key. The Obama plan would put more money into cutting-edge non-rocket space technology; give a 54 percent spending jump to money sent to private firms to develop ships to taxi astronauts to the International Space Station; and cut by nearly 12 percent spending to build the next government big rocket and capsule to carry astronauts. Congress in the past has cut the president's proposed spending on the private firms and technology and boosted the spending on the government big rocket and capsule.

—The president's 0.8 percent proposed increase in NASA science spending is his first proposed jump in that category in four years. It's also the first proposed jump in years in exploring other planets. It includes extra money for a 2020 unmanned Martian rover and continued funding for an eventual robotic mission to Jupiter's moon Europa. But the biggest extra science spending goes to study Earth.

— Obama's budget would cut aeronautics research 12 percent from current spending and slash NASA's educational spending by 25 percent. It also slightly trims the annual spending to build the over-budget multi-billion dollar James Webb Space Telescope, which will eventually replace the Hubble Space Telescope and is scheduled to launch in 2018.

The numbers:

Total spending: $18.5 billion

Spending that needs Congress' annual approval: $18.5 billion

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TRANSPORTATION

Up or down? Up 31 percent

What's new? A plan to tackle an estimated $2 trillion in deferred maintenance for the nation's aging infrastructure by boosting highway and transit spending to $478 billion over six years.

Highlights:

— The six-year highway and transit plan would get a one-time $238 billion infusion from the general treasury. Some of the money would be offset by taxing the profits of U.S. companies that haven't been paying taxes on income made overseas. That infusion comes on top of the $35 billion a year that normally comes from gasoline and diesel taxes and other transportation fees.

— The proposal also includes tax incentives to encourage private investment in infrastructure, and an infrastructure investment bank to help finance major transportation projects.

— The new infrastructure investment would be front-loaded. The budget proposes to spend the money over six years and pay for the programs over 10 years.

— The proposal also includes a new Interagency Infrastructure Permitting Improvement Center to coordinate efforts across nearly 20 federal agencies and bureaus to speed up the permitting process. For example, the Coast Guard, Corps of Engineers and Transportation Department are trying to synchronize their reviews of projects such as bridges that cross navigation channels.

The numbers:

Total spending: $94.5 billion, including more than $80 billion already required by law, mostly for highway and transit aid to states and improvement grants to airports.

Spending that needs Congress' annual approval: $14.3 billion.

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Associated Press writers Mary Clare Jalonick, Alan Fram, Kimberly Hefling, Dina Cappiello, Ricardo Alonso-Zaldivar, Seth Borenstein, Joan Lowy and Connie Cass contributed to this report.