Oldest bucket first
Aging is worked from the oldest bucket down, because that is where the deadlines are. Every claim in the queue gets a status and a next action rather than a note saying it was reviewed. Claims approaching a filing or appeal deadline are escalated ahead of larger but safer balances.
Actual payer calls
Portal status checks are quick but frequently useless — a portal will tell you a claim is "in process" for ninety days. Where the portal cannot resolve it, someone calls the payer, gets a representative and a reference number, and records what was said. That call log is yours.
Cleanup as a fixed-scope project
If the problem is a one-off backlog rather than an ongoing process, aged A/R cleanup can be scoped and quoted on its own without moving your day-to-day billing. You get a written read on what looks recoverable, what is past filing limits, and what should be written off, before committing to the work.