Guidance for 

Industry and FDA Staff 

FDA and Industry Actions on 

Premarket Notification (510(k)) 

Submissions: Effect on FDA Review 

Clock and Performance Assessment 

 Document issued on: May 21, 2004

For questions regarding submissions to the Center for Devices and Radiological Health, 

contact Heather S. Rosecrans at 240-276-4021 or by email at heather.rosecrans@fda.hhs.gov. 

For questions regarding submissions to the Center for Biologics Evaluation and Research, 

contact Leonard Wilson at 301-827-0373 or by email at wilsonl@cber.fda.gov. 

U.S. Department of Health and Human Services 

Food and Drug Administration 

Center for Devices and Radiological Health 

Center for Biologics Evaluation and Research 
Contains Nonbinding Recommendations 

Preface

Public Comment

Written comments and suggestions may be submitted at any time for agency consideration to 

Dockets Management Branch, Division of Management Systems and Policy, Office of 

Human Resources and Management Services, Food and Drug Administration, 5630 Fishers 

Lane, Room 1061, (HFA-305), Rockville, MD, 20852. Alternatively, electronic comments 

may be submitted to http://www.fda.gov/dockets/ecomments. Please identify your comments 

with the docket number listed in the notice of availability that publishes in the Federal 

Register announcing the availability of this guidance document. Comments may not be acted 

upon by the agency until the document is next revised or updated. 

Additional Copies 

Additional copies are available from the Internet at: 

http://www.fda.gov/cdrh/mdufma/guidance/1219.pdf or 

http://www.fda.gov/cber/mdufma/mdufma.htm, or by phone at (301) 827-2000 or (800) 835-

4709, or to receive this document by fax, call the CDRH Facts-On-Demand system at 800-

899-0381 or 301-827-0111 from a touch-tone telephone. Press 1 to enter the system. At the 

second voice prompt, press 1 to order a document. Enter the document number (1219) 

followed by the pound sign (#). Follow the remaining voice prompts to complete your 

request. 
Contains Nonbinding Recommendations 

Table of Contents 

I. Introduction....................................................................................................................... 1 

II. Purpose.............................................................................................................................. 2 

III. 510(k) Performance Goals............................................................................................ 2 

IV. FDA Actions................................................................................................................. 3

A. Issue an Order Declaring a Device SE.......................................................................... 3 

1. Criteria ...................................................................................................................... 4 

2. Effect on Review Clock............................................................................................ 4 

3. Effect on MDUFMA Goals ...................................................................................... 4 

B. Issue an Order Declaring a Device NSE....................................................................... 4 

1. Criteria ...................................................................................................................... 4 

2. Effect on Review Clock............................................................................................ 5 

3. Effect on MDUFMA Goals ...................................................................................... 5 

C. Request Additional Information (AI)............................................................................ 5 

1. Criteria ...................................................................................................................... 6 

2. Effect on Review Clock............................................................................................ 6 

3. Effect on MDUFMA Goals ...................................................................................... 7 

D. Advise the Submitter that the 510(k) is Not Required.................................................. 7 

a. Not-a-Device Decision................................................................................................. 7 

1. Criteria ...................................................................................................................... 8 

2. Effect on Review Clock............................................................................................ 8 

3. Effect on MDUFMA Goals ...................................................................................... 8 

b. Exempt from 510(k) Decision ..................................................................................... 8 

1. Criteria ...................................................................................................................... 8 

2. Effect on Review Clock............................................................................................ 8 

3. Effect on MDUFMA Goals ...................................................................................... 9 

E. Issue a Notice of Withdrawal........................................................................................ 9 

1. Criteria ...................................................................................................................... 9 

2. Effect on Review Clock............................................................................................ 9 

3. Effect on MDUFMA Goals .................................................................................... 10 

V. Industry Actions.............................................................................................................. 10 

A. Industry Submits a Response to an FDA Letter Requesting Additional Information 11 

1. Basis for Submission............................................................................................... 11 

2. Effect on Review Clock.......................................................................................... 11 

3. Effect on MDUFMA Goals .................................................................................... 11 

B. Industry Submits a Response to an Informal Request for Additional Information .... 11 

1. Basis for Submission............................................................................................... 12 

2. Effect on Review Clock.......................................................................................... 12 

3. Effect on MDUFMA Goals .................................................................................... 12 

C. Industry Requests Withdrawal of the 510(k).............................................................. 12 

1. Basis for the Request .............................................................................................. 12 

2. Effect on Review Clock.......................................................................................... 12 

3. Effect on MDUFMA Goals .................................................................................... 13 
Contains Nonbinding Recommendations 

D. Industry Requests an Extension of Time to Respond to an FDA Letter Requesting 

Additional Information ....................................................................................................... 13

1. Basis for the Request .............................................................................................. 13 

2. Effect on Review Clock.......................................................................................... 14 

3. Effect on MDUFMA Goals .................................................................................... 14 
Contains Nonbinding Recommendations 

Guidance for Industry and FDA Staff 

FDA and Industry Actions on Premarket 

Notification (510(k)) Submissions: 

Effect on FDA Review Clock 

and Performance Assessment 

This guidance represents the Food and Drug Administration's (FDA's) current thinking 

on this topic. It does not create or confer any rights for or on any person and does not 

operate to bind FDA or the public. You can use an alternative approach if the approach 

satisfies the requirements of the applicable statutes and regulations. If you want to discuss 

an alternative approach, contact the FDA staff responsible for implementing this 

guidance. If you cannot identify the appropriate FDA staff, call the appropriate number 

listed on the title page of this guidance. 

I. Introduction 

The Medical Device User Fee and Modernization Act of 2002 (MDUFMA), Public Law 

107-250, amends the Federal Food, Drug, and Cosmetic Act (the act) to provide the Food 

and Drug Administration (FDA) new responsibilities and resources. A provision of 

MDUFMA authorizes FDA to collect user fees for the review of certain premarket 

submissions received on or after October 1, 2002, including premarket notification 

submissions (510(k)s). The additional funds obtained from user fees will enable FDA, with 

the cooperation of industry, to improve the device review process to meet the performance 

goals identified in the letter from the Secretary of Health and Human Services to Congress 

(Goals Letter)1

 and summarized below. 

FDA’s guidance documents, including this guidance, do not establish legally enforceable 

responsibilities. Instead, guidances describe the agency’s current thinking on a topic and 

should be viewed only as recommendations, unless specific regulatory or statutory 

requirements are cited. The use of the word should in agency guidances means that 

something is suggested or recommended, but not required. 

 

1

 This letter can be found at http://www.fda.gov/cdrh/mdufma/pgoals.html) 

1
Contains Nonbinding Recommendations 

II. Purpose 

The purpose of this document is to assist agency staff and the device industry in 

understanding how various FDA and industry actions that may be taken on 510(k)s 

should affect the review clock for purposes of meeting the MDUFMA performance goals. 

III. 510(k) Performance Goals 

For 510(k) submissions, the performance goals contain both cycle (i.e., “first action” and 

“second and later action”) goals and decision goals. A “cycle” (or review cycle) is the 

period of time (in FDA days2

) beginning with the date FDA receives the 510(k)3 and 

ending with the date FDA issues a letter requesting additional information or announcing 

a “decision” (e.g., substantially equivalent (SE) or not substantially equivalent (NSE) 

determination). More than one cycle may occur before FDA issues its decision on the 

510(k) submission. 

The table below summarizes the 510(k) performance goals under MDUFMA. FDA has 

committed to meeting the following action and decision goals for a specified percentage 

of submissions, depending on the fiscal year: 

• an FDA decision (i.e., issuance of a SE or NSE determination letter) will issue 

within 90 days (cumulative FDA review time) 

• first action additional information (AI) letters will issue within 75 days 

• subsequent action additional information letters will issue within 60 days. 

Table 1. 510(k) Performance Goals

Performance Level (by FY)

(— indicates no quantitative goal) Action Review Time 

(FDA days)

2003 2004 2005 2006 2007

FDA decision 

90 — — 75% 75% 80%A

First AI letter 

75 — — 70% 80% 90%

 

2 The term “FDA days” refers to the amount of time a submission is under review by 

FDA and does not include the time when the clock has been stopped. 3 The recorded receipt date of a 510(k) submission is the date the submission is received 

by FDA or the date US Bank notifies FDA that payment of all fees due has been 

received, whichever is later. For additional information, see 

http://www.fda.gov/cdrh/devadvice/314a.html

2
Contains Nonbinding Recommendations 

Second or later AI letter 

60 — — 70% 80% 90%

AFY 2007 FDA decision goal (80% within 90 days) may be re-evaluated in consultation with 

industry to determine whether it is appropriate for FY 2007. 

IV. FDA Actions 

FDA may take any of the following actions on a 510(k) after FDA has conducted its 

review (21 CFR 807.100(a)): 

• issue an order declaring a device SE (SE letter) 

• issue an order declaring a device NSE (NSE letter) 

• request AI4 

• advise the submitter that the 510(k) submission is not required (i.e., product is not 

regulated as a device or device is exempt from the premarket notification 

requirements of the act) 

Further, in accordance with 21 CFR 807.87(l), the agency may consider a 510(k) to be 

withdrawn if additional information is not provided within 30 days following issuance of 

a request for additional information. In this instance, FDA may issue a notice of 

withdrawal.5

 

The following sections describe the actions FDA may take on 510(k)s, explain when 

these actions may be appropriate, and discuss the effect that each action has on the review 

clock and on the MDUFMA performance goals. 

A. Issue an Order Declaring a Device SE 

An order declaring a device to be SE is a letter issued to the submitter of a 

510(k) informing the submitter that FDA has determined that the device 

described in the 510(k) is substantially equivalent to a legally marketed 

device.6

 An order declaring a device to be SE authorizes marketing of the 

device in the United States (U.S.), subject to specific statutory and 

regulatory requirements of FDA.7

 

 

4

 Includes requests for a certification or disclosure statement as per 21 CFR 

807.100(a)(4). 

5

 A notice of withdrawal is sometimes referred to as a “deletion letter.” The term

“deletion” is used to differentiate a withdrawal under 21 CFR 807.87(l) from a request to 

withdraw a pending 510(k) by the submitter. 6

 See 21 CFR 807.92(a)(3) for the definition of “legally marketed device.” 

7

 See section 513(i) of the act. 

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Contains Nonbinding Recommendations 

1. Criteria 

The criteria for determining a device to be SE are described in 

section 513(i) of the act and in 21 CFR 807.100(b). Additional 

information relating to determinations of SE can be found in the 

guidance documents entitled,“Guidance on the Center for Devices 

and Radiological Health's Premarket Notification Review Program”

and “Determination of Intended Use for 510(k) Devices; Guidance 

for CDRH Staff.”8

 

2. Effect on Review Clock 

An SE decision is a decision that shuts off the review clock and marks the 

end of FDA review. The reported FDA review time for the 510(k) decision 

is the cumulative FDA days for all review cycles from the date the 510(k) is 

received to the date the SE letter is issued. 

3. Effect on MDUFMA Goals 

In accordance with the Goals Letter, to be counted as meeting the 

MDUFMA decision goals, the SE letter should issue within 90 FDA days 

from the date the 510(k) is received if it is the first action on the submission; 

or within 90 cumulative FDA days if the SE determination is a second or 

later action.

B. Issue an Order Declaring a Device NSE 

An order declaring a device to be NSE is a letter issued to the submitter of a 

510(k) informing the submitter that FDA has determined that the device 

described in the 510(k) is NSE to a legally marketed device and may not be 

introduced into commercial distribution in the U.S.9

1. Criteria 

In general, FDA issues an NSE letter in the following situations: 

• no predicate device exists 

• the device has a new intended use compared to the predicate device

• the device has different technological characteristics that raise 

different questions of safety and effectiveness than the predicate 

device 

 

8

 These two guidance documents are located at http://www.fda.gov/cdrh/k863.html and 

http://www.fda.gov/cdrh/ode/guidance/857.html, respectively. 9

 See section 513(i) of the act. 

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Contains Nonbinding Recommendations 

• the device has new indications for use or different technological 

characteristics than the predicate device and performance data10 on 

the device do not demonstrate that the device is as safe and effective 

as a legally marketed device. 

2. Effect on Review Clock 

An NSE determination is a decision that shuts off the review clock and 

marks the end of FDA review. The reported FDA review time for the 

510(k) decision is the cumulative FDA days for all review cycles from the 

date the 510(k) is received to the date the NSE letter is issued. 

 

3. Effect on MDUFMA Goals 

In accordance with the Goals Letter, to be counted as meeting the 

MDUFMA decision goals, the NSE letter should issue within 90 FDA days 

from the date the 510(k) is received if it is the first action on the submission; 

or within 90 cumulative FDA days from the date the 510(k) is received if 

the NSE determination is a second or later action. 

C. Request Additional Information (AI) 

FDA requests AI when the 510(k) lacks information necessary for the 

agency to begin, continue, or complete the review and make a determination 

as to whether the device is SE or NSE. Requests for additional information 

may be issued by letter, telephone, fax, or e-mail.11

a. Request AI by letter (“formal” AI request) 

A request for AI by letter refers to a request made (1) directly by letter 

or (2) first by telephone, fax, or e-mail, and then followed-up with a 

letter informing the submitter that the 510(k) is being placed on “hold” 

pending receipt of a response to all of the identified deficiencies. 

b. Request AI by means other than letter (“informal” AI request) 

An informal request for AI refers to a request made by telephone, fax, or 

e-mail, and not followed-up with a letter. An informal AI request does 

not result in the 510(k) being placed on “hold.” 

 

10 This may include data that are inadequate or inconclusive. 

11 For CDRH, refer to Blue Book memorandum entitled “Fax & E-mail Communication 

with Industry about Premarket Files Under Review,” located at 

http://www.fda.gov/cdrh/ode/a02-01.html; for CBER, request a secure e-mail account 

through the Regulatory Project Manager. 

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Contains Nonbinding Recommendations 

1. Criteria 

FDA requests AI when the information identified in 21 CFR 807.87 is not 

contained in the 510(k) submission. 

Note: FDA generally will utilize a maximum of three cycles of FDA review 

to reach a SE or NSE decision. The first review cycle begins upon receipt 

of the original 510(k) submission, and subsequent review cycles start when 

we receive responses to our requests for AI by letter. Thus, if there are 

multiple review cycles, FDA intends to issue a final decision following its 

review of industry’s response to a second AI request. In general, if 

unresolved deficiencies exist following FDA’s review of a response to a 

second AI request, FDA will issue an NSE letter.

a. Request AI by letter (formal AI request) 

FDA generally requests AI by letter when the agency believes the 

additional information is not minor in nature and/or cannot be provided 

within a reasonable period of time (i.e., such that the review will not be

delayed). 

b. Informal AI request 

FDA generally requests AI by means other than a letter when the agency 

believes the additional information is relatively minor in nature (e.g., a 

simple change to the device’s proposed labeling) and can be provided 

quickly. Such requests are generally made when FDA believes the 

submitter can address all of the information requested within a 

reasonable period of time that will not delay the review and the reviewer 

receives the 510(k) submitter’s commitment to providing the AI by the 

agreed upon time. 

2. Effect on Review Clock 

a. Request AI by letter (formal AI request) 

A request for AI by letter is an interim action that stops the review clock 

and marks the end of an FDA review cycle. The FDA review time for 

this 510(k) action is the number of FDA days for the review cycle. The 

review cycle begins on the date FDA receives the original 510(k) 

submission (or supplemental submission in response to an AI request 

letter) and ends on the date FDA issues the AI letter. 

b. Informal AI request 

An informal request for additional information does not stop the FDA 

review clock because the 510(k) remains under review. 

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Contains Nonbinding Recommendations 

Note: If FDA does not receive industry’s response to all of the 

deficiencies in the informal AI request within the agreed upon time, 

FDA may issue a letter placing the 510(k) on “hold” to stop the clock. 

3. Effect on MDUFMA Goals 

a. Request AI by letter (formal AI request) 

In accordance with the Goals Letter, to meet the MDUFMA decision 

goals, requests for AI should issue as early as possible in the review 

cycle so that the cumulative number of FDA review days does not 

exceed 90. In accordance with the Goals Letter, to be counted as 

meeting the MDUFMA cycle goals, FDA should issue the first AI 

request letter within 75 days from the date the original 510(k) 

submission is received or, for a second AI request, within 60 FDA days 

from the date of receipt of the submitter’s response to all of the 

deficiencies identified in the first AI request. 

b. Informal AI request 

This 510(k) action has no effect on the MDUFMA goals because this 

action does not affect the review clock. 

D. Advise the Submitter that the 510(k) is Not Required 

FDA believes that it is the responsibility of a manufacturer to initially 

determine whether a 510(k) submission is required based on the act, device 

regulations, and guidance documents. The Division of Small Manufactures 

Assistance, International, and Consumer Assistance, the Program Operations 

Staff, the review division, and product classification resources on the CDRH 

website at http://www.fda.gov/cdrh/devadvice/313.html can help you 

ascertain whether your device is exempt by regulation. You may also obtain 

information regarding the regulatory status of your device or product by 

submitting a 513(g) request.12 

 

a. Not-a-Device Decision 

 

12 For products regulated by CDRH, requests for classification information under section 

513(g) of the act should be submitted to the attention of the 513(g) Coordinator, Food and 

Drug Administration, Center for Devices and Radiological Health, 510(k) Document 

Mail Center (HFZ-401), 9200 Corporate Boulevard, Rockville, MD 20850. For products 

regulated by CBER, 513(g) requests should be submitted to the CBER Ombudsman, 

Center for Biologics Evaluations and Research, Suite 200 North, HFM-4, 1401 Rockville 

Pike, Rockville, MD 20852-1448. 

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Contains Nonbinding Recommendations 

A “not-a-device” letter informs the submitter that the product described in

the 510(k) is not regulated as a device. 

1. Criteria 

FDA sends a “not-a-device” letter when FDA has determined that the 

product described in the 510(k) does not meet the definition of “device” in

section 201(h) of the act. 

2. Effect on Review Clock 

The issuance of a “not-a-device” letter shuts off the review clock and marks 

the end of FDA review. The FDA review time for this 510(k) decision is 

the cumulative FDA days from the date the 510(k) is received to the date the 

not-a-device letter issues. 

3. Effect on MDUFMA Goals 

The MDUFMA goals do not include a performance goal for this action, so 

“not-a-device” decisions will not be counted towards the goals. 

Nevertheless, FDA intends to process 510(k)s with a not-a-device decision 

within a timely manner. 

b. Exempt from 510(k) Decision 

An “exempt” letter informs the 510(k) submitter that the device described in 

the 510(k) is classified as exempt from the premarket notification 

requirements of section 510(k) of the act. 

1. Criteria 

FDA sends an “exempt” letter when FDA determines that the device 

described in the 510(k) is exempt by regulation from the premarket 

notification requirements of section 510(k) of the act. Exemptions are found 

in 21 CFR 807.20(c), 807.65 and 807.85, as well as individual classification 

regulations (21 CFR Parts 862-892). 

2. Effect on Review Clock 

The issuance of an “exempt” letter is a decision that shuts off the review 

clock and marks the end of FDA review. The reported FDA review time for 

the 510(k) decision is the cumulative FDA days for all review cycles from 

the date the 510(k) is received to the date the exempt letter is issued. 

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Contains Nonbinding Recommendations 

3. Effect on MDUFMA Goals 

The MDUFMA goals do not include a performance goal for this action, so 

“exempt” decisions will not be counted towards the goals. Nevertheless, 

FDA intends to process 510(k)s with an exempt decision within a timely 

manner.

E. Issue a Notice of Withdrawal 

A notice of withdrawal informs the 510(k) submitter that FDA considers the 

510(k) to be withdrawn (21 CFR 807.87(l)). The letter represents a final 

FDA decision to end its review of the 510(k) submission because the 

submitter failed to submit a timely response to an AI letter that placed the 

submission on hold. 

1. Criteria 

FDA may issue a notice of withdrawal for a 510(k) that is on hold for AI if 

the submitter fails to submit a timely response to all of the deficiencies 

identified in the AI letter. In accordance with 21 CFR 807.87(l), FDA may 

consider a 510(k) to be withdrawn if the submitter fails to provide additional 

information within 30 days of a request. In the past, FDA has not strictly 

enforced this timeframe and has allowed submitters additional time to 

respond to requests for AI. The agency intends to continue this practice of 

allowing additional time. In general, FDA intends to issue a notice of

withdrawal in accordance with the following procedures: 

• If the submitter does not submit a written request for an extension to 

the Document Mail Center, as per 21 CFR 807.90, and does not 

provide a response to all of the deficiencies in the AI request within 

90 days of the request, FDA intends to consider the 510(k) to be 

withdrawn. 

• If the submitter does submit a written request for an extension and 

the request is received within 90 days of the date of the AI request, 

FDA intends to permit the 510(k) to remain on hold for up to 180 

days from the date of the AI request. FDA intends to consider the 

510(k) to be withdrawn if the agency does not receive a complete 

response to all of the deficiencies in the AI request within 180 days 

of the date of the AI request. 

2. Effect on Review Clock 

Because the 510(k) is on hold at the time the agency issues a notice of 

withdrawal, an FDA notice of withdrawal does not affect the time clock. The 

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Contains Nonbinding Recommendations 

FDA review time for this action will be measured as the number of days from the 

beginning of the FDA review until the request for AI. If there are multiple

requests for AI, subsequent cycles will begin when FDA receives a complete 

response to the AI and end when the agency sends out an additional request. 

3. Effect on MDUFMA Goals 

The MDUFMA goals do not include a decision goal for this action. 

However, the agency will report its performance on the cycle goals for those 

applications whose review ends with a notice of withdrawal. In accordance 

with the Goals Letter, to be counted as meeting the cycle goals, FDA should 

issue the first AI letter within 75 days from the date the agency receives the 

original 510(k) submission or, for a second AI request, within 60 days from

the date FDA receives the submitter’s response to all deficiencies identified 

in the first AI request. 

V. Industry Actions 

Industry actions after submitting a 510(k) are generally limited to providing AI to FDA. 

Submitters should provide information requested by FDA within the timeframes 

discussed below. 

Industry actions include the following submissions to a pending 510(k): 

• a response to an FDA letter requesting AI

• a response to an informal AI request 

• a request to withdraw the 510(k) 

• a request for an extension of time to respond to an FDA request for AI 

All of the above industry actions, with the exception of the submission of a response to 

an informal AI request, must be submitted by letter to the appropriate Center within FDA, 

in accordance with 21 CFR 807.90.13

The following sections describe the industry actions, explain the basis for each industry 

action, and discuss the effect that each action has on the review clock and on the 

MDUFMA performance goals. 

 

13 See “Fax & E-mail Communication with Industry about Premarket Files Under 

Review,” http://www.fda.gov/cdrh/ode/a02-01.html for additional information about 

time frames and responsibilities. 

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Contains Nonbinding Recommendations 

A. Industry Submits a Response to an FDA Letter 

Requesting Additional Information 

A response to an FDA AI letter is the submission of additional information, 

addressing identified deficiencies, that allows FDA to continue or complete 

the substantive review and make a decision on the 510(k). 

1. Basis for Submission 

The submitter should provide a complete response to a letter from FDA 

requesting AI. The response should address all of the deficiencies identified 

by the agency in its letter. 

2. Effect on Review Clock 

Industry’s submission of a response to an FDA AI letter is an action that, upon 

receipt by FDA, restarts the FDA review clock, i.e., a new 90-day review 

clock starts upon receipt of the AI. 

Note: If, however, FDA determines that the submitter has not addressed one 

or more of the deficiencies identified in the AI letter, the review cycle should 

be terminated until FDA receives a response addressing the remaining 

deficiencies. In such a case, FDA should inform the submitter by telephone, 

fax, or e-mail that the response is incomplete and, therefore, the clock has not

restarted. 

3. Effect on MDUFMA Goals 

In accordance with the Goals Letter, to be counted as meeting the 

MDUFMA decision goals, a final decision letter should issue within 90 

cumulative FDA days from the date the 510(k) is received. In accordance 

with the Goals Letters, to be counted as meeting the MDUFMA cycle goals, 

FDA should act on a submission containing a complete response to an FDA 

AI letter within 60 days of its receipt. 

B. Industry Submits a Response to an Informal Request for 

Additional Information 

A response to an informal request for AI is the submission to FDA of 

additional information, addressing previously identified deficiencies, by 

letter, telephone, fax, or e-mail, that allows the agency to continue or

complete the substantive review and make a decision on the 510(k). 

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Contains Nonbinding Recommendations 

1. Basis for Submission 

The submitter should provide a response to all of the deficiencies after 

receiving FDA’s informal request for AI. 

Note: As explained above in Section IV(C), FDA makes an informal 

request for AI when FDA believes the submitter can address all of the 

information requested within a reasonable period of time that will not 

adversely affect the review and the reviewer receives the submitter’s 

commitment to providing the AI by the agreed upon time. 

2. Effect on Review Clock 

Industry’s submission of a response to an informal FDA request for AI is an 

action that does not affect the review clock because the 510(k) remains under 

review while the request is pending. 

Note: If the agency does not receive industry’s response to all of the 

deficiencies within the agreed upon time, FDA may issue a letter placing the 

510(k) on “hold” and stop the review clock. 

3. Effect on MDUFMA Goals 

Industry’s submission of a response to a FDA informal request for AI has no 

effect on the MDUFMA goals because this action does not affect the review 

clock. 

C. Industry Requests Withdrawal of the 510(k) 

A request to withdraw a 510(k) informs the agency of the submitter’s 

intention to discontinue its pursuit of FDA review of the device at this 

time.14 

1. Basis for the Request 

The 510(k) submitter may request withdrawal of the pending 510(k) at any 

time, and for any reason, after it is submitted for review but before FDA 

renders its final decision. 

2. Effect on Review Clock 

Industry’s submission of a request to withdraw a pending 510(k) is an action that 

shuts off the review clock. If the 510(k) is under review at the time FDA receives 

 

14 See “Fax & E-mail Communication with Industry about Premarket Files Under 

Review,” http://www.fda.gov/cdrh/ode/a02-01.html for information on 510(k) 

withdrawal procedures.

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the withdrawal request, the review clock should stop on that date. If the 510(k) is 

on hold at the time FDA receives the withdrawal request, the review clock should 

remain stopped as of the date the 510(k) was last placed on hold for AI. The 

reported FDA review time for the 510(k) is the cumulative FDA days for all 

review cycles from the date the submission is originally received to the date the 

withdrawal request is received, or the date the submission was last placed on hold, 

as applicable. 

3. Effect on MDUFMA Goals 

The MDUFMA goals do not include a decision goal for this action. 

However, the agency will report its performance on the cycle goals for 

applications whose review ends with a request for withdrawal. In 

accordance with the Goals Letter, to be counted as meeting the cycle goals, 

FDA should issue the first AI letter within 75 days from the date the agency 

receives the original 510(k) submission or, for a second AI request, within 

60 days from the date of receipt of the submitter’s response to all 

deficiencies identified in the first AI request. 

D. Industry Requests an Extension of Time to Respond to an 

FDA Letter Requesting Additional Information 

An industry request for an extension of time to respond to an AI letter 

informs the agency of the 510(k) submitter’s wish to extend the response 

time identified in FDA’s request. 

1. Basis for the Request 

In the past, FDA has not strictly enforced the 30 day timeframe identified in 

requests for AI and has allowed submitters additional time to respond to such 

requests. The agency intends to continue to allow additional time for 

responses. If the submitter needs more than 90 days to respond to the 

deficiencies in an AI letter, the submitter should send a letter requesting an 

extension to the Document Mail Center. 

Note: FDA intends to issue a notice of withdrawal if it does not receive a 

request for additional time.15 (Refer to section IV. E. Issue a Notice of 

Withdrawal for additional discussion of FDA actions regarding requests for 

extension.) Even in those situations where a submitter does request an 

extension, FDA does not intend to keep 510(k)s indefinitely on hold while 

 

15 In accordance with 21 CFR 807.87(l), FDA may consider a 510(k) to be withdrawn if 

the submitter fails to provide additional information within 30 days of a request. As 

explained in Section IV. E., FDA generally permits submitters additional time to respond 

to such requests. 

13
Contains Nonbinding Recommendations 

14

awaiting the AI. Therefore, in general, FDA intends to issue a notice of 

withdrawal if the submitter, who has requested an extension, fails to provide 

a complete response within 180 days from the date of the AI request. 

2. Effect on Review Clock 

A request for an extension of time to respond to an AI request does not affect

the FDA review clock because the 510(k) remains on hold. 

3. Effect on MDUFMA Goals 

Industry’s submission of a request for an extension has no effect on the 

MDUFMA goals because this action does not affect the review clock.