The Internal Revenue Service’s audit rate has been lower this decade than in most taxpayers’ lifetimes, a New York Times analysis shows, and if the Trump administration follows through with plans to cut the agency’s work force, audits will almost certainly become even rarer.

The most recent I.R.S. data shows the audit rate of individual taxpayers has decreased by about two-thirds since 2010.

Exact comparisons of audit rates are challenging because the I.R.S. has changed its definitions over time. But the Times analysis of historical I.R.S. data found that the effective audit rates between 2020 and 2023, all under 0.5 percent, were lower than any published audit rate since at least 1950.

In 1980, the agency’s published audit rate was over 2 percent, and in 1960 it was over 3 percent.

In the 2010s, audit rates plunged for all income levels. For most Americans, an audit might have been a one-in-100 event at the beginning of the decade. By the end of the decade, it was even less likely.