API Reference

Retirement Plan Administration

Plan lifecycle (401k, 403b, 457b, SEP, SIMPLE), participant enrollment, vesting schedules, real-time contribution processing, §402(g)/§415(c) IRS limit enforcement, on-demand ADP/ACP nondiscrimination testing, and SECURE 2.0 RMD tracking. Runs on https://api.interposehq.com.