# Late 401(k) contributions reported: methodology notes

Population: 401(k)-type plans filing Schedule H for plan years ending in 2024. The as-filed denominator is 53,806 filings. The reporting numerator is 13,528 affirmative line 4a flags, for 25.14%.

File vintage: 2026-09-25. Extraction date: 2026-10-22. The DOL EBSA 2024 Latest Schedule H and Form 5500 research files were used.

The unit is filings, not employers, plans, people, participants, or accounts. Eight duplicate EIN-plus-plan-number pairs yield a 25.15% deduplicated sensitivity result. There are 13,528 affirmative flags and 13,529 positive amounts.

The exact median is $33,882.50 using linear interpolation. Concentration uses floor top-k rules: 135 largest filings for 1% and 1,352 for 10%.

Line 4a reporting can include prior-year carryovers, corrected violations, and certain late participant-loan repayments. Reporting prevalence is not actual violation incidence and is not an established upper or lower bound on that incidence. Reported dollars are not participant losses.