How long do you have to appeal an insurance denial?

If you only remember one thing from this article, remember this: the single most important deadline for your appeal is printed on your denial letter, and you should calendar it the day the letter arrives. Insurance appeal deadlines are unforgiving. Miss the window and you generally lose the right to challenge the denial, no matter how strong your case is. This guide explains how long you have to appeal an insurance denial, broken down by plan type, plus the decision timelines insurers must meet and what to do if you are running out of time.

The one rule that beats every chart: read your denial letter

Every legitimate denial of a health insurance claim has to tell you how to appeal and how long you have to do it. That information lives in the "appeal rights" or "your rights" section of the notice. The deadline on your letter controls, because plans can give you more time than the legal minimum but never less. So before you trust any general number, find the date on your own notice.

Do this immediately. The appeal clock generally starts when you receive the denial, not when you get around to reading it. Keep the envelope, note the day it arrived, and write the appeal deadline on your calendar with a reminder a week before. If your denial appeared in an online portal, screenshot the posting date. When the receipt date is ambiguous, count from the earlier date to give yourself a margin of safety.

ERISA employer plans: at least 180 days to appeal internally

If your coverage comes from a private-sector employer, your plan is almost certainly governed by ERISA (the Employee Retirement Income Security Act). For these group health plans, federal law sets a clear floor for the internal appeal deadline: at least 180 days from the date you receive the adverse benefit determination, under 29 CFR 2560.503-1(h)(3)(i). The plan may grant a longer window, but it cannot shorten this below 180 days. That makes the appeal deadline for an ERISA plan one of the most generous in the system, but it is still a hard line. For a deeper walkthrough of how these appeals work, see our guide to ERISA appeals.

One caution: 180 days is the floor for the standard internal appeal. Different rules and shorter practical timelines can apply to urgent care situations and to the external review stage that follows, both covered below. Always cross-check the exact date on your letter.

How fast the insurer must decide your appeal

The deadline runs both ways. Once you file, ERISA group health plans have to decide within set timeframes under 29 CFR 2560.503-1(i), with urgent care defined and handled under 29 CFR 2560.503-1(f):

• Pre-service denials (care you need authorized before you get it): a decision within 30 days of your appeal.
• Post-service denials (care already provided, now a billing dispute): a decision within 60 days.
• Urgent care appeals: a decision within 72 hours. Urgent appeals can usually be started by phone; follow up in writing the same day.
• Concurrent care (an ongoing hospital stay or course of treatment the plan wants to cut short): the decision must come before the approved care ends, in time for you to appeal before coverage stops.

These timelines matter to you, not just the insurer, because a plan that blows its own deadline can hand you a procedural advantage, as the deemed-exhaustion section below explains.

External review: typically about four months after the final denial

If your internal appeals fail, most non-grandfathered plans must offer an independent external review by an outside reviewer who does not work for your insurer. Under the ACA framework at 45 CFR 147.136, you generally have up to four months (120 days) from the date of the final internal denial to request external review. This is the external review deadline people most often miss, because it feels like the fight is already over once the insurer says no for the last time. It is not. External reviewers overturn a meaningful share of denials. Learn how the process works in our guide to independent external review (IRO).

State-run external review programs can set different windows and procedures, so the 120-day figure is the federal default, not a universal guarantee. Confirm the exact deadline on your final denial notice. If you are unsure or the notice is unclear, your state insurance department can tell you which external review process applies to your plan and how long you have.

Medicare and Medicaid have their own, separate deadlines

The ERISA and ACA numbers above apply to private employer and individual-market coverage. Medicare and Medicaid run entirely separate appeal systems with their own timelines, and those timelines differ from the private-plan rules. Within Medicare, the deadlines and steps for Original Medicare differ from those for Medicare Advantage plans.

Because these numbers vary by program, do not assume a deadline you read for a private plan applies to your Medicare or Medicaid denial. Read the appeal-rights section of your specific notice (for example, a Medicare Summary Notice, a Medicare Advantage denial, or a state Medicaid notice) and follow the deadline it states. When in doubt, call the number on the notice and ask for the appeal deadline in writing.

What happens if you miss the deadline

Missing an insurance appeal deadline usually means you lose the right to appeal that denial. The insurer can decline to consider a late appeal, and that decision is hard to undo. Some processes recognize narrow good cause exceptions, for instance a serious illness that kept you from filing, or a denial notice that never properly reached you, but these exceptions are discretionary, fact-specific, and not something to rely on.

If your deadline is close, do not wait until your appeal is perfect. File a short letter now stating that you are appealing the denial and will supplement the record with additional evidence, then send the supporting documents as soon as they are ready. A timely, bare-bones appeal beats a polished one that arrives a day late.

Deemed exhaustion: when the insurer's missed deadline helps you

Deadlines bind the insurer too. Under 29 CFR 2560.503-1(l), if an ERISA plan fails to follow its own claims procedures or misses its decision deadline, you may be deemed to have exhausted the internal appeal process. In plain terms, if the plan does not decide your appeal on time, you may be able to move straight to external review or court without waiting for a decision the plan never properly made.

To use this, document everything: the date you filed, the applicable decision deadline, and the date it passed with no proper response. Keep copies of every letter and a log of every call. That paper trail is what turns the insurer's missed deadline into your procedural advantage.

Your deadline checklist

• Find the appeal deadline on your denial letter and calendar it today, with a reminder one week out.
• ERISA employer plan: at least 180 days to file the internal appeal (29 CFR 2560.503-1(h)(3)(i)).
• External review: typically about 120 days from the final internal denial (45 CFR 147.136); confirm the exact date on your notice.
• Medicare or Medicaid: deadlines differ by program; follow the date on your specific notice.
• Running out of time: file a brief appeal now and supplement it later.
• Insurer missed its own deadline: note the dates; you may be deemed to have exhausted internal appeals.

Knowing how long you have to appeal an insurance denial is half the battle. The other half is filing something strong before the clock runs out. Counterclaim can draft an appeal letter for your specific denial in minutes, citing the law and clinical evidence that applies to your case, so a tight deadline does not turn into a missed one.