Timely filing denials are one of the most preventable revenue leaks in RCM — and UnitedHealthcare is one of the most unforgiving payers when you miss the window. Here's a precise breakdown of how UHC's timely filing requirements actually work.

The Standard Commercial Rule: 90 Days from DOS

For most UnitedHealthcare commercial plans, claims must be submitted within 90 days of the date of service (DOS). This applies to professional claims (CMS-1500) and outpatient facility claims. The 90-day window is strict — there's no grace period baked in, and UHC's internal systems will auto-deny anything outside this window at the claim level.

Inpatient Hospital Claims Are Different

This is where most billing teams get caught. For inpatient hospital stays, the 90-day clock starts from the discharge date, not admission. If a patient is admitted December 1st and discharged December 28th, your deadline is March 28th — not March 1st. Make sure your EMR/PM system is pulling the discharge date, not the admission date, when it calculates timely filing windows.

Emergency Services: Same 90-Day Rule

Emergency department claims follow the standard 90-day DOS rule. No extended window for emergencies — UHC does not make an exception here for commercial products (Medicare Advantage is different — more on that below).

COB Claims: The Clock Resets

Coordination of Benefits (COB) claims — where UHC is secondary — are the most misunderstood. The 90-day window for secondary claims runs from the date of the primary payer's Explanation of Benefits (EOB), not the date of service. This matters enormously. If you're billing UHC secondary and the primary EOB takes 60 days to come back, you still have 90 days from that EOB date to submit. Don't let your billing system calculate from DOS on secondary claims — it will generate false urgency and potentially cause you to skip proper primary adjudication.

Medicare Advantage Plans: Different Rules Apply

UHC Medicare Advantage plans are governed by CMS requirements, which mandate a 12-month timely filing window from date of service. This is a significant difference from commercial. If your team is applying 90-day rules to MA claims, you're likely writing off recoverable revenue. Confirm plan type before applying any deadline — UHC's own admin guide distinguishes these clearly.

Retroactive Eligibility: The Clock Resets Again

When a patient's eligibility is confirmed retroactively — common with Medicaid coordination or late enrollment — UHC resets the timely filing clock to 90 days from the date eligibility was confirmed, not from DOS. Document the retroactive eligibility notification date carefully. This is your defense if you need to appeal a denial on retroactive grounds.

What to Do When You Miss the Window

If you do receive a timely filing denial, your first move is to pull proof of timely filing — a clearinghouse acknowledgment with the original submission date, or a portal confirmation timestamp. UHC will reconsider if you can demonstrate the claim was submitted within the window and denied for another reason, then resubmitted. Document everything at the time of original submission.

Bottom Line

UHC's timely filing rules are straightforward on paper but generate denials in volume because teams apply a single rule across claim types. Commercial vs. MA, professional vs. inpatient, primary vs. secondary — each has its own clock. Build these distinctions into your billing workflows now, and you'll prevent a significant share of timely filing denials before they happen.