Only candidates seeking nomination by a political party to the office of President are eligible to receive primary matching funds. A presidential candidate must establish eligibility by showing broad-based public support. He or she must raise more than $5,000 in each of at least 20 states (that is, over $100,000). Although an individual may contribute up to a specific limit to a primary candidate, only a maximum of $250 of each individual’s contribution is counted in determining whether a candidate has met the $5,000 threshold in each state. This means that a candidate must receive contributions from a minimum of 20 contributors in each of at least 20 states in order to establish eligibility for primary matching funds.

Presidential candidates also must agree to:

Limit campaign spending for all primary elections combined to $10 million plus a cost-of-living adjustment (COLA). This national spending limit was $48.07 million in 2016 .

Limit campaign spending in each state to $200,000 plus COLA, or to a specified amount based on the number of voting age individuals in the state (plus COLA), whichever is greater. In 2016, state limits ranged from $961,400 in Wyoming to $23,092,100 in California .

Limit spending from personal funds to $50,000.

The campaign finance law exempts the payment of some expenses from the spending limits. Certain fundraising expenses (up to 20 percent of the expenditure limit) and legal and accounting expenses incurred solely to ensure the campaign's compliance with the law do not count against the expenditure limits.

Even if they no longer campaign actively in primary elections, candidates may continue to request public funds to pay off campaign debts until the first Monday of March of the year following an election. However, to qualify for matching funds, contributions must be deposited in the campaign account by December 31 of the election year. Eligible candidates may receive public funds equaling up to half of the national spending limit for the primary campaign.