There are two answers to this question and you need both. The legal ceiling is the number of days your plan is allowed to take before it is in violation. The real-world median is how long it usually takes. As of September 2026 those two numbers are far apart: the ceiling is 7 calendar days for most standard requests, and the median is about one day.
Everything below is the current rule as of September 2026, including the changes that took effect January 1, 2026 under the CMS Interoperability and Prior Authorization final rule. If you want the mechanics of how the process works and what to do about a denial, that is on the prior authorization page. This page is the clock.
The Decision Clocks by Plan Type
| Plan type | Standard decision | Expedited / urgent decision | Source |
|---|---|---|---|
| Employer or ACA marketplace plan, pre-service claim | 15 days, extendable once by 15 days | 72 hours | 29 CFR 2560.503-1 |
| Medicare Advantage, service subject to prior authorization | 7 calendar days | 72 hours | 42 CFR 422.568(b)(1)(ii), 422.572(a)(1) |
| Medicare Advantage, service not subject to those rules | 14 calendar days | 72 hours | 42 CFR 422.568(b)(1)(i) |
| Medicare Advantage Part B drug | 72 hours, no extension | 24 hours, no extension | 42 CFR 422.568(b)(3), 422.572(a)(2) |
| Medicare Part D drug | 72 hours | 24 hours | 42 CFR 423.568(b), 423.572(a) |
| Medicaid and CHIP, fee-for-service and managed care | 7 calendar days | 72 hours | CMS-0057-F |
| Washington state-regulated plan, electronic request | 3 calendar days | 1 calendar day | RCW 48.43.830 |
| Washington state-regulated plan, non-electronic request | 5 calendar days | 2 calendar days | RCW 48.43.830 |
The 15-day commercial figure is the ERISA claims-procedure rule at 29 CFR 2560.503-1, and the same timeframes reach individual and marketplace coverage through the federal internal-claims-and-appeals requirements. KFF, reviewing the 2025 plan data, states the marketplace standard-request deadline as 15 days, which matches.
Five details in that table are worth spelling out.
The Medicare Advantage split is new. Before 2026, every standard organization determination ran on a single 14-calendar-day clock. Section 422.568(b)(1) now carves out services subject to the prior authorization rules in 42 CFR 422.122 and gives those a 7-calendar-day clock beginning on or after January 1, 2026. Everything else stays at 14 days.
Drugs run on their own faster clocks. A Medicare Part B drug decision is due in 72 hours standard and 24 hours expedited, and neither period can be extended. Part D coverage determinations are the same, 72 hours and 24 hours. Drug requests are the fastest category in Medicare and the most likely to feel slow anyway, because of the supporting-statement problem described below.
The urgent-care clock in commercial plans has a hidden second stage. Under 29 CFR 2560.503-1(f)(2)(i), a plan has 72 hours to decide an urgent claim, but only 24 hours to tell you if information is missing. You then get at least 48 hours to supply it, and the plan gets 48 hours after that. A stalled urgent request can therefore legitimately run past 72 hours without the plan breaking any rule.
Extensions are real and they are long. Medicare Advantage plans may extend a standard determination by up to 14 additional calendar days if you request it, if evidence is needed from a non-contract provider, or in extraordinary circumstances. They must tell you in writing why. A 7-day clock can lawfully become 21.
States can be stricter, and many are. Washington is the tightest example found as of September 2026: under RCW 48.43.830, a carrier must decide an electronic standard request in 3 calendar days and an electronic expedited request in 1 calendar day, with 5 and 2 days respectively for non-electronic submissions, for plans issued or renewed on or after January 1, 2024. Washington also bars carriers from using artificial intelligence as the sole means of denying, delaying, or modifying care. State rules only reach state-regulated insurance, so they do not apply to a self-funded employer plan.
What Actually Happens: About One Day
2026 was the first year plans had to publish their own prior authorization numbers, and KFF’s August 13, 2026 analysis of that 2025 data is the best picture available.
- Standard requests: median 0.9 days, just under 22 hours, across all three markets. Medicare Advantage and Medicaid managed care both came in at 1 day, the ACA marketplace at 0.9 days.
- Expedited requests: median 0.4 days (just under 10 hours) in Medicare Advantage, 0.8 days (about 19 hours) in Medicaid managed care, and 1 day in the ACA marketplace.
- Spread across insurers matters more than the average. Median standard response times ran from under 1 day at CVS, Humana, and Kaiser Permanente to 2 days at Centene in Medicare Advantage, from 1 day to 4 days at CareSource in Medicaid managed care, and from under 1 day to 4 days at Molina in the marketplace.
Two cautions before you take comfort in those numbers. A median means half of all requests took longer than the figure shown, and plans are only required to report medians and averages, not the share of decisions that blew the deadline. And these figures cover decisions, not outcomes: KFF found insurers denied 12% of standard requests in Medicare Advantage, 14% in Medicaid managed care, and 18% in the ACA marketplace that year.
What Actually Makes It Take Longer
Missing information stops the clock. This is the single biggest cause of a slow authorization. Under 29 CFR 2560.503-1(f)(4), when a plan extends a deadline because you failed to submit needed information, the clock is tolled from the date the extension notice goes out until you respond. For a Medicare Part D exceptions request the effect is even starker: the 72-hour clock does not start until your prescriber’s supporting statement arrives, and if it never arrives, the plan simply waits 14 calendar days and then has another 72 hours. That is a 17-day path to a decision without anyone breaking a rule.
A denial resets the whole timeline. The clocks above cover the initial decision. An appeal is a separate process on its own schedule. HHS OIG’s June 8, 2026 report on skilled nursing facility admissions found that Medicare Advantage enrollees who appealed a denial waited a median of 6 days from the original request to the final appeal decision, and 17% waited 10 days or more. When the same plans approved the request outright, they typically did it the same day. The report also found that 95% of appealed SNF denials, 2,313 of 2,445, were ultimately overturned in the enrollee’s favor.
Evidence from an out-of-network provider. If the plan needs records from a non-contract provider, that is an explicit ground for a 14-day extension in Medicare Advantage.
Peer-to-peer scheduling. When a case goes to a peer-to-peer call between your physician and the plan’s medical director, the calendar of two busy doctors becomes the rate limit.
Submission method. Faxed and mailed requests are slower than electronic ones everywhere, and Washington’s statute prices the difference at two extra days. The Prior Authorization API required of Medicare Advantage, Medicaid, CHIP, and federal marketplace plans beginning January 1, 2027 is aimed squarely at this gap.
What to Do While You Wait
Ask for expedited handling. The urgent track is the single largest lever available, and it is your provider who has to pull it. Ask the office to submit the request as expedited and to state in the submission why the standard timeframe could seriously jeopardize your health or your ability to regain maximum function, which is the statutory standard across plan types.
Use the Part D transition supply if you are new to a plan. Under 42 CFR 423.120, a Part D plan must give you a one-time temporary supply of at least an approved month’s worth of a drug during your first 90 days in a new plan, and that requirement explicitly covers formulary drugs flagged for prior authorization or step therapy. Written notice follows within 3 business days. See Medicare Part D and drug formulary.
Price the cash route in parallel, not afterward. If the self-pay price is close to what your cost sharing would have been anyway, the wait is not worth it. Manufacturer and nonprofit programs often move faster than an appeal: see prescription assistance programs.
Track the deadline and use it. If a Medicare Advantage plan misses its timeframe, 42 CFR 422.568(f) and 422.572(f) make that failure itself an adverse organization determination you can appeal immediately. A Part D plan that misses its deadline must forward your request to an independent review entity within 24 hours automatically. Note the date and time the request was submitted, and get that from your provider’s office in writing.
Start the appeal the day the denial lands. Given a median 6-day appeal timeline in the OIG’s SNF data and overturn rates of 67% in Medicare Advantage, 47% in Medicaid managed care, and 43% in the ACA marketplace per KFF, waiting to decide whether to appeal costs you days you cannot get back. See how to appeal a health insurance denial, the template in insurance appeal letter, and for Medicare specifically, Medicare appeal.
The Bottom Line
The legal maximum for a standard prior authorization is 7 calendar days in Medicare Advantage, Medicaid, and CHIP as of January 1, 2026, and 15 days in commercial and marketplace plans, with 72 hours the near-universal ceiling for urgent requests. The typical decision lands in about a day. If yours has been sitting for more than three or four days without a request for additional information, something has gone wrong: call the plan, get the submission date and the deadline in writing, and ask your provider whether the request can be resubmitted as expedited.