Fees for universities and four-year colleges in the U.S. and Canada
JSTOR partners with higher education institutions across the United States and Canada to expand access to scholarship.
Explore classification criteria, fees, and participation options that ensure equitable, sustainable access to journals, books, images, and digital stewardship services for your campus community.
Classifications
JSTOR classifications are modeled on the Carnegie Classifications. If your institution does not have a classification, contact us with the following details:
- Total number of active annual print serials subscriptions taken by your institution’s library (including all departmental or faculty libraries and both foreign and domestic titles)
- Total number of volumes in your institution’s library (including all departmental and faculty libraries)
- Number of students at your institution (or full-time staff and researchers if you are not an academic institution)
- Number of faculty members at your institution
Archival journals and primary sources
Flexible options for access and participation
Higher education institutions can choose from two archival journals and primary sources fee model options:
- Full journals and primary sources model: Provides immediate access to the JSTOR Archival Journals and Primary Sources Collection, a single collection of all licensed journal and primary source content.
- Individual collections model: Enables institutions to license individual multi-discipline, discipline-specific, and primary source collections.
Full journals and primary sources model
Gain immediate access to all of JSTOR’s licensed archival journals and primary sources through one streamlined collection.
New JSTOR participants
The benefits of the model for new to JSTOR participants:
- Your institution gains immediate access to all licensed archival journals and primary source content on JSTOR.
- Full access begins with a minimum starting fee that is 20% of the full fee for the collection, and gradually increases annually until you reach the full fee.
- One time-payment (OTP) contributions for individual collections further reduce the full AAF for the collection.
How it works:
- Universities and four-year colleges opt-in to the fee model. Opting in provides immediate access to the JSTOR Archival Journals and Primary Sources Collection, a single collection of all licensed journal and primary source content.
- The minimum starting fee for the Archival Journals and Primary Sources Collection is 20% of the full fee for the collection.
- Institutions gradually increase to the collection’s full fee via a 5% annual fee adjustment. Annual fee adjustments stop when institutions reach the full AAF for the collection.
- The full AAF of the Archival Journals and Primary Sources Collection is based on an institution’s classification, which for institutions in the United States and Canada is modeled on the Carnegie Classifications and other library metrics in the global community. One time-payment (OTP) contributions for individual collections also lower the full AAF, with one year of OTP AAF deducted from the full AAF for the collection.
| Classification | Minimum starting AAF for the Archival Journals and Primary Sources Collection* |
|---|---|
| Very large | $27,000 |
| Large | $16,600 |
| Medium | $10,000 |
| Small | $6,400 |
| Very small | $3,600 |
*For the minimum starting AAF outside the US, please contact your Outreach representative or Licensing Agent.
| Classification | Archival Journals and Primary Sources Collection full AAF* |
|---|---|
| Very large | $135,000 |
| Large | $83,000 |
| Medium | $50,000 |
| Small | $32,000 |
| Very small | $18,000 |
*For the Archival Journals and Primary Sources Collection full AAF outside the US, please contact your Outreach representative or Licensing Agent.
Current JSTOR participants
The benefits of the model for current JSTOR participants:
- Your institution gains immediate access to all archival journals and primary source content on JSTOR that is available for licensed access.
- Full access begins with your institution’s current total Annual Access Fees (AAF) plus a modest adjustment of 2%-5% that continues to be applied annually until you reach the full fee. Please note: A minimum starting fee that is 20% of the full fee for the collection applies.
- Your current archive investment influences the annual fee adjustment.
- One time-payment (OTP) contributions for individual collections further reduce the full AAF for the collection.
How it works:
- Universities and four-year colleges opt-in to the fee model. Opting-in provides immediate access to the JSTOR Archival Journals and Primary Sources Collection, a single collection of all licensed journal and primary source content.
- The starting fee is based on the current level of total archive participation in Annual Access Fees (AAF) plus a modest adjustment of 2%-5% that continues to be applied annually until you reach the full fee. The annual fee adjustment percentage is based on the number of collections an institution currently licenses to recognize current investment. Please note: A minimum starting fee that is 20% of the full fee for the collection applies.
- Annual fee adjustments stop when institutions reach the full AAF for the collection.
- The full AAF of the Archival Journals and Primary Sources Collection is based on an institution’s classification, which for institutions in the United States and Canada is modeled on the Carnegie Classifications and other library metrics in the global community. One time-payment (OTP) contributions for individual collections also lower the full AAF, with one year of OTP AAF deducted from the full AAF for the collection. Institutions eventually reach the same AAF for their respective classification, but the number of years to get there varies. This ensures institutions are comparably priced over time.
| Total collections currently licensed | Annual fee adjustment |
|---|---|
| 1-7 | 5% |
| 8-18 | 3% |
| 19+ | 2% |
| Classification | Archival Journals and Primary Sources Collection full AAF* |
|---|---|
| Very large | $135,000 |
| Large | $83,000 |
| Medium | $50,000 |
| Small | $32,000 |
| Very small | $18,000 |
*For the Archival Journals and Primary Sources Collection full AAF outside the US, please contact your Outreach representative or Licensing Agent.
Individual multi-discipline and discipline-specific collections
| Fees Legend | |
|---|---|
| Annual Access Fee (AAF) | Recurring fee paid each year for a collection |
| One-time payment | One-time payment for new archive collections |
| One-time payment conversion | Convert collections licensed under our standard AAF model to one-time payment |
Very small
| Multi-discipline collection | Standard option (AAF) | One-time payment (OTP) option | One-time payment (OTP) conversion |
|---|---|---|---|
| Arts & Sciences I | $2,060 | $35,020 | Yes |
| Arts & Sciences II | $1,030 | $17,510 | Yes |
| Arts & Sciences III | $1,339 | $22,763 | Yes |
| Arts & Sciences IV | $1,236 | $21,012 | Yes |
| Arts & Sciences V | $1,339 | $22,736 | Yes |
| Arts & Sciences VI | $1,339 | $22,736 | Yes |
| Arts & Sciences VII | $1,030 | $17,510 | Yes |
| Arts & Sciences VIII | $1,030 | $17,510 | Yes |
| Arts & Sciences IX | $1,030 | $17,510 | Yes |
| Arts & Sciences X | $824 | $14,008 | Yes |
| Arts & Sciences XI | $773 | $13,141 | Yes |
| Arts & Sciences XII | $721 | $12,257 | Yes |
| Arts & Sciences XIII | $690 | $11,730 | Yes |
| Arts & Sciences XIV | $618 | $10,506 | Yes |
| Arts & Sciences XV | $1,236 | $21,012 | Yes |
| Life Sciences | $1,957 | $33,269 | Yes |
| Discipline-specific collection | Standard option (AAF) | One-time payment (OTP) option | One-time payment (OTP) conversion |
|---|---|---|---|
| Asia Collection | $1,405 | N/A | N/A |
| Business & Economics | $2,772 | N/A | N/A |
| Business I | $1,030 | N/A | N/A |
| Business II | $515 | N/A | N/A |
| Business III | $515 | N/A | N/A |
| Business IV | $515 | $8,755 | Yes |
| Hebrew Journals | $216 | $3,672 | Yes |
| Iberoamérica | $960 | N/A | N/A |
| Ireland Collection | $258 | $4,386 | Yes |
| Jewish Studies | $271 | $4,607 | Yes |
| Language & Literature | $721 | N/A | N/A |
| Lives of Literature | $892 | $15,164 | Yes |
| Mathematics & Statistics | $1,411 | N/A | N/A |
| Music | $1,000 | N/A | N/A |
| Public Health | $515 | $8,755 | Yes |
| Religion & Theology | $730 | N/A | N/A |
| Security Studies | $696 | $11,832 | Yes |
| Sustainability | $878 | $14,926 | Yes |
| Primary source collection | Standard option (AAF) | One-time payment (OTP) option | One-time payment (OTP) conversion |
|---|---|---|---|
| 19th Century British Pamphlets | $258 | $4,386 | Yes |
| Struggles for Freedom: Southern Africa | $783 | $13,311 | Yes |
| World Heritage Sites: Africa | $309 | $5,253 | Yes |
| Global Plants | $773 | $13,141 | Yes |
Small
| Multi-discipline collection | Standard option (AAF) | One-time payment (OTP) option | One-time payment (OTP) conversion |
|---|---|---|---|
| Arts & Sciences I | $3,090 | $52,530 | Yes |
| Arts & Sciences II | $1,288 | $21,896 | Yes |
| Arts & Sciences III | $2,369 | $40,273 | Yes |
| Arts & Sciences IV | $2,266 | $38,522 | Yes |
| Arts & Sciences V | $2,369 | $40,273 | Yes |
| Arts & Sciences VI | $2,369 | $40,273 | Yes |
| Arts & Sciences VII | $2,060 | $35,020 | Yes |
| Arts & Sciences VIII | $1,854 | $31,518 | Yes |
| Arts & Sciences IX | $2,060 | $35,020 | Yes |
| Arts & Sciences X | $1,545 | $26,265 | Yes |
| Arts & Sciences XI | $1,442 | $24,514 | Yes |
| Arts & Sciences XII | $1,339 | $22,763 | Yes |
| Arts & Sciences XIII | $1,277 | $21,709 | Yes |
| Arts & Sciences XIV | $1,133 | $19,261 | Yes |
| Arts & Sciences XV | $2,060 | $35,020 | Yes |
| Life Sciences | $3,863 | $65,671 | Yes |
| Discipline-specific collection | Standard option (AAF) | One-time payment (OTP) option | One-time payment (OTP) conversion |
|---|---|---|---|
| Asia Collection | $2,492 | N/A | N/A |
| Business & Economics | $5,002 | N/A | N/A |
| Business I | $1,545 | N/A | N/A |
| Business II | $1,030 | N/A | N/A |
| Business III | $1,030 | N/A | N/A |
| Business IV | $1,030 | $17,510 | Yes |
| Hebrew Journals | $330 | $5,610 | Yes |
| Iberoamérica | $1,779 | N/A | N/A |
| Ireland Collection | $515 | $8,755 | Yes |
| Jewish Studies | $412 | $7,004 | Yes |
| Language & Literature | $1,030 | N/A | N/A |
| Lives of Literature | $1,556 | $26,452 | Yes |
| Mathematics &Statistics | $2,217 | N/A | N/A |
| Music | $1,947 | N/A | N/A |
| Public Health | $1,030 | $17,510 | Yes |
| Religion & Theology | $1,327 | N/A | N/A |
| Security Studies | $1,216 | $20,672 | Yes |
| Sustainability | $1,533 | $26,061 | Yes |
| Primary source collection | Standard option (AAF) | One-time payment (OTP) option | One-time payment (OTP) conversion |
|---|---|---|---|
| 19th Century British Pamphlets | $412 | $7,004 | Yes |
| Struggles for Freedom: Southern Africa | $1,174 | $19,958 | Yes |
| World Heritage Sites: Africa | $464 | $7,888 | Yes |
| Global Plants | $1,288 | $21,896 | Yes |
Medium
| Multi-discipline collection | Standard option (AAF) | One-time payment (OTP) option | One-time payment (OTP) conversion |
|---|---|---|---|
| Arts & Sciences I | $4,120 | $70,040 | Yes |
| Arts & Sciences II | $2,060 | $35,020 | Yes |
| Arts & Sciences III | $3,605 | $61,285 | Yes |
| Arts & Sciences IV | $3,399 | $57,783 | Yes |
| Arts & Sciences V | $3,605 | $61,285 | Yes |
| Arts & Sciences VI | $3,605 | $61,285 | Yes |
| Arts & Sciences VII | $3,090 | $52,530 | Yes |
| Arts & Sciences VIII | $2,884 | $49,028 | Yes |
| Arts & Sciences IX | $3,090 | $52,530 | Yes |
| Arts & Sciences X | $2,575 | $43,775 | Yes |
| Arts & Sciences XI | $2,472 | $42,024 | Yes |
| Arts & Sciences XII | $2,266 | $38,522 | Yes |
| Arts & Sciences XIII | $2,163 | $36,771 | Yes |
| Arts & Sciences XIV | $1,854 | $31,518 | Yes |
| Arts & Sciences XV | $3,193 | $54,281 | Yes |
| Life Sciences | $6,180 | $105,060 | Yes |
| Discipline-specific collection | Standard option (AAF) | One-time payment (OTP) option | One-time payment (OTP) conversion |
|---|---|---|---|
| Asia Collection | $3,901 | N/A | N/A |
| Business & Economics | $7,477 | N/A | N/A |
| Business I | $2,266 | N/A | N/A |
| Business II | $1,545 | N/A | N/A |
| Business III | $1,545 | N/A | N/A |
| Business IV | $1,545 | $26,265 | Yes |
| Hebrew Journals | $659 | $11,203 | Yes |
| Iberoamérica | $2,772 | N/A | N/A |
| Ireland Collection | $1,030 | $17,510 | Yes |
| Jewish Studies | $824 | $14,008 | Yes |
| Language & Literature | $1,545 | N/A | N/A |
| Lives of Literature | $2,562 | $43,554 | Yes |
| Mathematics & Statistics | $3,225 | N/A | N/A |
| Music | $2,975 | N/A | N/A |
| Public Health | $1,545 | $26,265 | Yes |
| Religion & Theology | $2,105 | N/A | N/A |
| Security Studies | $2,001 | $34,017 | Yes |
| Sustainability | $2,521 | $42,857 | Yes |
| Primary source collection | Standard option (AAF) | One-time payment (OTP) option | One-time payment (OTP) conversion |
|---|---|---|---|
| 19th Century British Pamphlets | $567 | $9,639 | Yes |
| Struggles for Freedom: Southern Africa | $1,957 | $33,269 | Yes |
| World Heritage Sites: Africa | $773 | $13,141 | Yes |
| Global Plants | $2,060 | $35,020 | Yes |
Large
| Multi-discipline collection | Standard option (AAF) | One-time payment (OTP) option | One-time payment (OTP) conversion |
|---|---|---|---|
| Arts & Sciences I | $6,695 | $113,815 | Yes |
| Arts & Sciences II | $5,150 | $87,550 | Yes |
| Arts & Sciences III | $6,180 | $105,060 | Yes |
| Arts & Sciences IV | $5,150 | $87,550 | Yes |
| Arts & Sciences V | $6,180 | $105,060 | Yes |
| Arts & Sciences VI | $6,180 | $105,060 | Yes |
| Arts & Sciences VII | $5,150 | $87,550 | Yes |
| Arts & Sciences VIII | $5,150 | $87,550 | Yes |
| Arts & Sciences IX | $5,150 | $87,550 | Yes |
| Arts & Sciences X | $4,635 | $78,795 | Yes |
| Arts & Sciences XI | $4,429 | $75,293 | Yes |
| Arts & Sciences XII | $4,223 | $71,791 | Yes |
| Arts & Sciences XIII | $4,017 | $68,289 | Yes |
| Arts & Sciences XIV | $3,708 | $63,036 | Yes |
| Arts & Sciences XV | $4,738 | $80,546 | Yes |
| Life Sciences | $9,991 | $169,847 | Yes |
| Discipline-specific collection | Standard option (AAF) | One-time payment (OTP) option | One-time payment (OTP) conversion |
|---|---|---|---|
| Asia Collection | $6,999 | N/A | N/A |
| Business & Economics | $10,993 | N/A | N/A |
| Business I | $3,296 | N/A | N/A |
| Business II | $2,575 | N/A | N/A |
| Business III | $2,060 | N/A | N/A |
| Business IV | $2,060 | $35,020 | Yes |
| Hebrew Journals | $989 | $16,813 | Yes |
| Iberoamérica | $4,783 | N/A | N/A |
| Ireland Collection | $1,545 | $26,265 | Yes |
| Jewish Studies | $1,236 | $21,012 | Yes |
| Language & Literature | $3,090 | N/A | N/A |
| Lives of Literature | $4,463 | $75,871 | Yes |
| Mathematics & Statistics | $5,240 | N/A | N/A |
| Music | $5,028 | N/A | N/A |
| Public Health | $2,060 | $35,020 | Yes |
| Religion & Theology | $3,706 | N/A | N/A |
| Security Studies | $3,487 | $59,279 | Yes |
| Sustainability | $4,393 | $74,681 | Yes |
| Primary source collection | Standard option (AAF) | One-time payment (OTP) option | One-time payment (OTP) conversion |
|---|---|---|---|
| 19th Century British Pamphlets | $773 | $13,141 | Yes |
| Struggles for Freedom: Southern Africa | $3,131 | $53,227 | Yes |
| World Heritage Sites: Africa | $1,236 | $21,012 | Yes |
| Global Plants | $3,193 | $54,281 | Yes |
Very large
| Multi-discipline collection | Standard option (AAF) | One-time payment (OTP) option | One-time payment (OTP) conversion |
|---|---|---|---|
| Arts & Sciences I | $8,755 | $148,835 | Yes |
| Arts & Sciences II | $8,240 | $140,080 | Yes |
| Arts & Sciences III | $10,300 | $175,100 | Yes |
| Arts & Sciences IV | $9,785 | $166,345 | Yes |
| Arts & Sciences V | $10,300 | $175,100 | Yes |
| Arts & Sciences VI | $10,300 | $175,100 | Yes |
| Arts & Sciences VII | $8,240 | $140,080 | Yes |
| Arts & Sciences VIII | $8,755 | $148,835 | Yes |
| Arts & Sciences IX | $9,785 | $166,345 | Yes |
| Arts & Sciences X | $7,725 | $131,325 | Yes |
| Arts & Sciences XI | $7,468 | $126,956 | Yes |
| Arts & Sciences XII | $7,159 | $121,703 | Yes |
| Arts & Sciences XIII | $6,798 | $115,566 | Yes |
| Arts & Sciences XIV | $6,386 | $108,562 | Yes |
| Arts & Sciences XV | $8,034 | $136,578 | Yes |
| Life Sciences | $15,450 | $262,650 | Yes |
| Discipline-specific collection | Standard option (AAF) | One-time payment (OTP) option | One-time payment (OTP) conversion |
|---|---|---|---|
| Asia Collection | $11,808 | N/A | N/A |
| Business & Economics | $19,273 | N/A | N/A |
| Business I | $6,180 | N/A | N/A |
| Business II | $4,120 | N/A | N/A |
| Business III | $3,605 | N/A | N/A |
| Business IV | $3,605 | $61,285 | Yes |
| Hebrew Journals | $1,442 | $24,514 | Yes |
| Iberoamérica | $8,148 | N/A | N/A |
| Ireland Collection | $2,060 | $35,020 | Yes |
| Jewish Studies | $1,803 | $30,651 | Yes |
| Language & Literature | $5,150 | N/A | N/A |
| Lives of Literature | $7,573 | $128,741 | Yes |
| Mathematics & Statistics | $8,465 | N/A | N/A |
| Music | $7,551 | N/A | N/A |
| Public Health | $3,605 | $61,285 | Yes |
| Religion & Theology | $6,240 | N/A | N/A |
| Security Studies | $5,916 | $100,572 | Yes |
| Sustainability | $7,454 | $126,718 | Yes |
| Primary source collection | Standard option (AAF) | One-time payment (OTP) option | One-time payment (OTP) conversion |
|---|---|---|---|
| 19th Century British Pamphlets | $979 | $16,643 | Yes |
| Struggles for Freedom: Southern Africa | $3,914 | $66,538 | Yes |
| World Heritage Sites: Africa | $1,545 | $26,265 | Yes |
| Global Plants | $3,914 | $66,538 | Yes |
Books at JSTOR
Publisher Collections
Publisher Collections is a Books at JSTOR model that offers a streamlined way to acquire and access high-quality scholarly ebook collections from trusted academic publishers. Each of the 20+ collections includes a perpetual JSTOR license to current-year title sets, access to backlist titles on JSTOR for active participants, and an equitable tiered fee structure.
The annual fees below are based on your JSTOR classification. If you do not know your classification, please contact us.
| Publisher collection | Very small | Small | Medium | Large | Very large |
|---|---|---|---|---|---|
| Berghahn Books | $1,500 | $3,000 | $5,000 | $8,000 | $10,000 |
| Cornell University Press | $1,500 | $2,500 | $3,000 | $5,500 | $10,000 |
| Duke University Press | $7,000 | $8,000 | $9,500 | 11,000 | $13,000 |
| Fordham University Press | $1,000 | $1,500 | $2,000 | $3,000 | $4,500 |
| Indiana University Press | $500 | $750 | $1,000 | $1,500 | $2,000 |
| Leuven University Press | $700 | $850 | $1,000 | $1,200 | $1,500 |
| Liverpool University Press | $5,000 | $12,000 | $18,000 | $20,000 | $25,000 |
| NYU Press | $2,500 | $3,500 | $4,500 | $6,500 | $8,500 |
| Pluto Press | $1,000 | $1,500 | $2,000 | $3,500 | $4,500 |
| State University of New York Press | $1,500 | $2,500 | $3,500 | $6,000 | $10,000 |
| Syracuse University Press | $1,500 | $1,750 | $2,000 | $2,250 | $2,750 |
| University of Arizona Press | $1,000 | $1,500 | $2,000 | $2,500 | $3,500 |
| University of Illinois Press | $2,500 | $3,000 | $4,000 | $6,000 | $9,000 |
| University of Nebraska Press | $1,000 | $1,250 | $1,500 | $2,000 | $2,500 |
| University of North Carolina Press | $1,000 | $1,500 | $2,500 | $3,500 | $4,500 |
| University of South Carolina Press | $1,000 | $1,250 | $1,500 | $2,000 | $2,500 |
| University of Utah Press | $700 | $850 | $1,000 | $1,250 | $1,500 |
| University of Wisconsin Press | $750 | $1,000 | $1,250 | $1,500 | $2,000 |
| University Press of Florida | $1,000 | $1,500 | $2,500 | $3,500 | $4,500 |
| University Press of Kansas | $1,000 | $1,250 | $1,500 | $2,000 | $3,000 |
| University Press of Kentucky | $1,000 | $1,500 | $2,000 | $2,500 | $3,500 |
| University Press of Mississippi | $1,000 | $1,500 | $2,750 | $3,500 | $5,000 |
Path to Open
Academic institutions pay an annual Path to Open participation fee to access a growing corpus of titles exclusively available on JSTOR. At the start of the third year following the publication date, titles will be converted to open access (OA).
Fees for unlimited, exclusive access to the full set of titles are tiered based on the participating institution’s JSTOR classification. If you do not know your classification, please contact us.
| Classification | Annual fee* | 2025-2026 pilot pricing (1,000 titles) |
|---|---|---|
| Very Large | $15,000 | $30,000 |
| Large | $10,000 | $20,000 |
| Medium | $7,500 | $15,000 |
| Small | $5,000 | $10,000 |
| Very Small | $2,500 | $5,000 |
*This includes 300 new copyright titles released each year, in addition to earlier published titles prior to converting to open access.
Artstor collection
The annual fees below are based on your classification, which is modeled on the Carnegie Classifications. If you do not know your classification, please contact us.
| Very small | Small | Medium | Large | Very large |
|---|---|---|---|---|
| $2,500 | $4,250 | $6,950 | $11,500 | $16,000 |
Digital Stewardship Services
JSTOR Digital Stewardship Services is a seamless, cloud-hosted platform that unites digital asset management, long-term preservation, and expanded discovery pathways—including sharing on JSTOR—with the AI-assisted collections processing tools of JSTOR Seeklight.
Our tiered service model ensures that institutions of all sizes can access solutions that align with their goals. Compare features or contact us to determine the best fit for your needs. The fees below are based on your JSTOR classification.
Tier 1: Share on JSTOR
Share collections on JSTOR, making them discoverable alongside scholarly research. Includes audio/video hosting, usage analytics, and indexing in search engines and library discovery services.
Annual fees for universities and four-year colleges in the U.S. and Canada begin at $1,500.
Tier 2: Preserve, manage, and share
Everything in Tier 1, plus digital asset management with flexible cataloging tools, broader sharing options, and OAIS-compliant preservation.
Annual fees for universities and four-year colleges in the U.S. and Canada begin at $6,000.
Tier 3: AI-assisted stewardship charter program
Everything in Tiers 1 and 2, plus the AI-powered tools of JSTOR Seeklight for accelerating collections processing—from description to transcription and analysis—while maintaining expert oversight and control.
Charter program* participants join a growing community of institutions partnering with JSTOR to advance responsible, AI-assisted digital stewardship through shared learning, collaboration, and continuous feedback.
Annual Tier 3 charter fees for universities and four-year colleges in the U.S. and Canada begin at $8,000.
*Open to institutions with Tier 3 licenses active by or before 12/31/2025
Let’s connect
Get tailored pricing for your institution
Every institution is unique—your pricing should be too. Tell us a bit about your organization, and we’ll match you with the right JSTOR access and participation options.
Note: Items marked with * are required.
Get tailored pricing for your institution
Every institution is unique—your pricing should be too. Tell us a bit about your organization, and we’ll match you with the right JSTOR access and participation options.
Note: Items marked with * are required.