The budget deal passed by Congress last week, called the Bipartisan Budget Act of 2015, funds the government for two years and extends the debt ceiling to March 15, 2017. Included in the measure is $80 billion in new spending (half for defense and half for social programs).

How does Congress expect to pay for the new spending? Tax changes, of course. Most of the changes are directed at larger companies. Here are the three key changes:

• Raise money from better auditing of large partnerships. The deal repeals the partnership audit rules created by the Tax Equity and Fiscal Responsibility Act of 1982, replacing them with a new audit regime. Under the deal, there is a general rule about who should be recognized as a partner, making it easier to conduct audits. The change won’t affect most partnerships and limited liability companies (LLCs) that file partnership returns; it’s aimed at large law firms, hedge funds, and other highly profitable businesses that the government suspects are not paying all of the taxes they should. The new rules also let the IRS collect any adjustments from the partnership rather than the partners, likely at the highest individual income tax rate.

• End the automatic health coverage enrollment. The Affordable Care Act had required employers with more than 200 employees to automatically enroll them in health plans. This rule has been repealed. I can’t explain how this raises revenue.

• Reduce the required contributions to pension plans. The deal increases the interest rate used to figure required contributions to qualified benefit (pension) plans that are underfunded. By increasing the rate, it reduces required contributions, which in turn, reduces tax deductions (i.e., generates more revenue).

The Joint Committee on Taxation estimates that these changes could result in $11.22 billion in revenue over 10 years. You do the math: $80 billion in new spending versus $11.22 billion in new revenue (assuming that the estimates are borne out). But anyway, the budget deal does not do some other things, including:

• Extending provisions that expired at the end of 2014. It’s the 11th month of 2015 and the tax rules for this year are still unknown. You may recall that more than 50 provisions expired at the end of last year. It may be that we’ll have to wait until mid-December, as we did last year, to know what tax breaks apply for 2015.

• Changing payroll tax rates. You may read that there’s been a change in payroll taxes, but the fact is the tax rates are unchanged. The budget deal merely reallocates a portion of collections to the Disability Insurance Trust Fund in 2016 through 2018.

Reasonable people can differ on the wisdom on the overall budget deal. No one in his or her right mind should think that with the questionable numbers for spending versus revenue and the uncertain status of the tax laws that Congress is doing a good job.