Legal basis for &quot;discretionary spending&quot; vs. &quot;mandatory spending&quot; in the USA
<h4>1. &quot;Discretionary&quot; and &quot;mandatory&quot; dollars</h4>
<p>My general understanding of the federal budget process in the USA is that:</p>
<ul>
<li><a href="https://en.wikipedia.org/wiki/Discretionary_spending" rel="nofollow noreferrer">discretionary spending</a> must be &quot;appropriated&quot; by the House of Representatives every year, following ideas from Article I Sections 7 or 9 or something.</li>
<li><a href="https://en.wikipedia.org/wiki/Mandatory_spending" rel="nofollow noreferrer">mandatory spending</a> is not subject to this requirement.</li>
</ul>
<h4>2. This Congress can't bind a future Congress (?)</h4>
<p>However, my layman's understanding of Congress's power also includes the notion that &quot;this Congress can't bind a future Congress&quot;.  Googling around has provided many instances of politicians and even law professors invoking this notion, but no authoritative source.   Some (perhaps only weak) form of this principle must be true; otherwise this Congress could say &quot;no new laws can be passed after 2030 except by a 4/5s majority in Congress&quot; or whatever, effectively stripping future Congresses of all of their power.</p>
<h4>3. So, &quot;mandatory&quot; for whom?</h4>
<p>Thus I think my question is, for whom is the spending &quot;mandatory&quot;?  Future Congresses?  Could they just do a simple majority vote (assuming the President signs it) to alter &quot;mandatory&quot; spending?  If so, is it really &quot;mandatory&quot;?  And how would it then substantively differ from &quot;discretionary&quot; spending?  Is &quot;mandatory&quot; really just an escape clause from requiring Appropriations by the House of Representatives?</p>

<p>&quot;Mandatory&quot; spending means spending that takes place without passage of a new appropriation bill, but it may still be modified by Congress. The only truly mandatory spending categories that cannot be modified by future Congresses are interest on the national debt and certain multiple year contractual obligations (e.g. for naval ship building contracts).</p>
<p>&quot;Discretionary&quot; spending means spending that has to be appropriated each budget cycle. Without affirmative legislation, each budget cycle, it doesn't happen.</p>
<p>The distinction is important because the U.S. federal legislative process is frequently gridlocked with divided control with the President's political party (which has veto power), or with a division of partisan control between the two houses of Congress, each of which have veto power over the legislative process.</p>
<p>It takes the approval of both houses of Congress and the President to pass legislation except in the case of a rare veto override or a Senate and President approved treaty, which requires a two-thirds majority, and appropriations bills have to start in the U.S. House. If all three are not controlled by the same party, getting legislation passes as is necessary for discretionary spending, is challenging. So the status quo default of mandatory spending is hard to modify.</p>

<p>My understanding is that &quot;Discretionary&quot; and &quot;Mandatory&quot; spending terms are not legal terms so much as political terms.</p>
<p>A future Congress certainly can legally choose to reduce spending on an essential service like Social Security checks, or interest payments on US Debt, but it would have significant social and political repercussions that leave Congress with very little choice but to continue the spending with at most minor changes.</p>
<p>If they did make substantial changes, the results could be disastrous. If Social Security payments were significantly cut, Senior Citizens could be unable to pay rent, or go hungry.  If interest payments weren't reliable, the Credit of the USA would be demolished, and we would likely be in an instant Economic Depression.</p>
<p>This spending is termed &quot;Mandatory&quot;.</p>
<hr>
<p>The wiki article you linked to in your question even states:</p>
<blockquote>
<p>Congress can only reduce the funding for programs by changing the authorization law itself. This requires a 60-vote majority in the Senate to pass.</p>
</blockquote>
<p>So, Congress can change, reduce, or eliminate &quot;Mandatory&quot; spending, but it is more difficult to do so.</p>
<hr>
<p>For more overview information:
<a href="https://www.newamerica.org/education-policy/topics/federal-education-legislation-budget/federal-education-budget/federal-budget-process/mandatory-and-discretionary-spending/" rel="noreferrer">https://www.newamerica.org/education-policy/topics/federal-education-legislation-budget/federal-education-budget/federal-budget-process/mandatory-and-discretionary-spending/</a></p>

united-states constitutional-law finance