Form S-11MEF Files Dataset

The Form S-11MEF Files Dataset is a complete EDGAR collection of Rule 462(b) "additional securities" registration statements filed on Form S-11MEF, the form-specific companion to Form S-11 used by real estate investment trusts and other real-estate-focused issuers. Each record is a single EDGAR submission identified by its 18-digit accession number, pairing a structured metadata.json header with the primary S-11MEF registration statement and its non-image exhibits. Filings are made by issuers that already have an effective Form S-11 and need to register up to an additional 20 percent of the maximum aggregate offering price of the same securities class, typically at the moment of pricing an upsized REIT IPO or follow-on. Coverage runs from April 1996, the effective date of Rule 462(b), to the present, and the dataset is distributed as monthly ZIP containers organized by year and month.

Update Frequency
Daily
Updated at
2026-04-15
Earliest Sample Date
1996-04-01
Total Size
1.4 MB
Total Records
417
Container Format
ZIP
Content Types
TXT, JSON, HTML
Form Types
S-11MEF

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Dataset Index JSON API

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Dataset Files

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2026-03.zip16.1 KB6 records
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2019-03.zip14.9 KB4 records
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2018-01.zip36.8 KB14 records
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2013-05.zip14.6 KB5 records
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1997-09.zip12.6 KB11 records
1997-08.zip245.1 KB5 records
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1996-11.zip9.5 KB4 records
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What This Dataset Contains

The dataset materializes every Form S-11MEF submission accepted by EDGAR. Form S-11MEF is a short-form registration statement filed under Rule 462(b) of the Securities Act of 1933 to register up to an additional 20 percent of securities for an offering already registered on a previously effective Form S-11. Form S-11 itself is the dedicated registration form for REITs and other issuers whose business is principally the acquisition and holding of real estate or interests in real estate; the "MEF" suffix marks the Rule 462(b) "additional securities" filing that piggybacks on the underlying S-11. The MEF submission becomes effective immediately upon filing, so the document is intentionally a thin wrapper: it incorporates the prior S-11 by reference and adds only the disclosures and exhibits needed to register the incremental securities and compute the additional fee.

On disk a record materializes as a folder named after its accession number with the dashes stripped (for example 000162828025002725), nested inside a monthly ZIP archive organized as {year}/{year}-{month}.zip. The dataset is distributed in the ZIP container format, and the per-record file types are TXT, JSON, and HTML, with HTML accounting for nearly all per-record bytes in modern filings. As a structural consequence of the Rule 462(b) mechanic, every S-11MEF record references two distinct file numbers: a newly assigned S-11MEF file number unique to the MEF submission itself, and the prior effective S-11 file number that the MEF augments.

Content Structure of a Single Record

A record has two layers. The outer layer is the per-accession folder, which contains exactly one metadata.json plus one HTML file per non-image document in the original EDGAR submission. The inner layer is the SGML-wrapped HTML content of each document. The dataset deliberately omits image attachments (referenced inside the submission as GRAPHIC documents, typically .jpg signature graphics or logos) and also omits the consolidated full-submission .txt file even though both are enumerated in metadata.json; only the JSON header and the non-image documents are materialized on disk.

Within the folder, document filenames are issuer-chosen (a common pattern is {issuer}-sx11mef.htm for the primary document and exhibit{n}{m}-sx11mef.htm for exhibits, e.g. exhibit107-sx11mef.htm, exhibit51-sx11mef.htm) and are not normalized by the dataset publisher. The reliable mapping from logical document to file is metadata.json -> documentFormatFiles[].documentUrl, which preserves the issuer-supplied filename and the EDGAR <SEQUENCE> ordering.

The SGML <DOCUMENT> envelope

Every HTML file in the folder is wrapped in EDGAR's classic SGML <DOCUMENT> envelope. The envelope opens with <DOCUMENT> and declares four header lines before the HTML body:

  • <TYPE> — the canonical document type (S-11MEF, EX-FILING FEES, EX-5.1, EX-8.1, EX-23.1, etc.).
  • <SEQUENCE> — the integer position in the submission, matching the corresponding documentFormatFiles[].sequence value.
  • <FILENAME> — the issuer-supplied filename, identical to the on-disk name.
  • <DESCRIPTION> — a short human-readable label.

A <TEXT> block follows, inside which the full <html> document lives, ending with </TEXT></DOCUMENT>. The HTML inside <TEXT> is a complete page with its own <head> and <body>. Modern submissions are typically generated by EDGAR-aware composition tools — Workiva/Wdesk markers such as <!-- Document created using Wdesk --> are frequently visible at the top of the HTML — and use inline <font> and table-based styling rather than external stylesheets. Older filings exhibit a wider range of HTML conventions and, in the earliest years of coverage, plain-ASCII rendering with no HTML markup at all.

metadata.json field shape

metadata.json is the structured per-accession header. Its fields are:

  • formType — always "S-11MEF" for this dataset.
  • accessionNo — the dashed 18-digit accession number (for example "0001628280-25-002725").
  • filedAt — ISO-8601 timestamp with timezone offset capturing the moment of filing acceptance.
  • effectivenessDate — the effectiveness date, which for S-11MEF coincides with the filing date because Rule 462(b) makes the MEF effective upon filing.
  • description — a human-readable form description, typically "Form S-11MEF - Registration adding securities to prior Form S-11 registration [Rule 462(b)]".
  • linkToFilingDetails — URL of the primary HTML document on sec.gov.
  • linkToTxt — URL of the complete SGML submission text file on sec.gov.
  • linkToHtml — URL of the EDGAR filing-index page.
  • linkToXbrl — empty; S-11MEF filings do not carry XBRL data.
  • documentFormatFiles — ordered array describing every document in the EDGAR submission. Each entry exposes sequence, size (bytes, as a string), documentUrl, description, and type. The type is the canonical EDGAR type and is identical to the <TYPE> line in the corresponding SGML wrapper. The terminal entry, with an empty sequence and type, refers to the full-submission .txt. Image documents appear as GRAPHIC-type entries even though their bytes are not shipped on disk.
  • dataFiles — empty; no XBRL or data-file attachments are associated with this form type.
  • seriesAndClassesContractsInformation — empty; this concept applies to investment-company filers, while S-11MEF issuers are operating REITs.
  • entities — an array of filer entity objects. For S-11MEF this is typically a single Filer carrying companyName (with a (Filer) suffix), cik, fileNo (the new file number assigned to the S-11MEF submission itself, distinct from the prior S-11 number cited in the body), type (S-11MEF), act (33 for the Securities Act of 1933), filmNo (the EDGAR film number), irsNo (sometimes 000000000 when unreported), stateOfIncorporation, fiscalYearEnd in MMDD form, sic (overwhelmingly [6798 Real Estate Investment Trusts](https://www.osha.gov/sic-manual/6798), consistent with the form's REIT-focused scope), and a tickers array.
  • id — an opaque dataset identifier for the record.

The two file numbers — the new S-11MEF fileNo in entities[0] and the predecessor S-11 file number — are not joined in the metadata layer. Consumers needing to chain a MEF back to its underlying S-11 must extract the prior file number from the body text or from the EX-5.1 and EX-FILING FEES exhibits, where it is consistently cited.

The S-11MEF document body

The primary document carries <TYPE>S-11MEF in its SGML wrapper, but its visible cover-page title is "FORM S-11" because the MEF is filed on the same form as its predecessor with a Rule 462(b) box checked. The body is short and follows a fixed four-part shape:

  1. Cover page. Registrant name, state of organization, principal executive office address, agent for service of process, copies-to counsel addresses, and the standard Form S-11 checkboxes. The Rule 462(b) box is checked, and the registrant inserts the prior effective Form S-11 file number into the adjacent blank. The cover concludes with the standard boilerplate stating that the Registration Statement shall become effective upon filing in accordance with Rule 462(b).

  2. Explanatory Note and Incorporation by Reference. A short narrative that (a) recites the prior S-11 file number and effective date, (b) incorporates the prior S-11 registration statement by reference in its entirety, and (c) quantifies the incremental offering with precise share or dollar figures, explicitly attesting that the additional securities do not exceed 20% of the maximum aggregate offering price previously registered. For underwritten REIT IPOs and follow-ons, the explanatory note frequently itemizes the incremental shares attributable to the underwriters' option.

  3. PART II — Information Not Required in Prospectus, Item 36 ("Exhibits"). An exhibit index lists the exhibits filed with the MEF and re-references exhibits previously filed under the predecessor S-11. Entries filed concretely with the MEF (commonly EX-5.1, EX-8.1, EX-23.1, EX-FILING FEES) hyperlink to the in-folder HTML; entries previously filed (Power of Attorney 24.1, articles of incorporation, underwriting agreement, and similar prior exhibits) hyperlink back to the underlying S-11 on EDGAR.

  4. Signatures. Executed signature block, with the registrant, the date, and the signatures of the principal executive officer, principal financial officer, principal accounting officer, and a quorum of directors. Because the MEF is effective on filing, the signatures bear the same date as filedAt in metadata.json.

All substantive disclosure — the prospectus, risk factors, business description, property tables, financial statements, MD&A, management and compensation, and the legal and regulatory sections required by Form S-11 — lives in the prior S-11 and is not re-filed in the MEF.

Typical exhibits

Beyond the primary S-11MEF document, a record typically contains a small, predictable set of exhibits, each wrapped in its own SGML <DOCUMENT> envelope with an exhibit-specific <TYPE>:

  • EX-FILING FEES (Exhibit 107). The Rule 457(o) Calculation of Filing Fee Table, in the structured tabular format required by the SEC's Filing Fee Disclosure rule. Captures Security Type (e.g. "Equity"), Security Class Title (e.g. "Common Stock, $0.01 par value per share"), Amount Registered, Proposed Maximum Offering Price Per Share, Maximum Aggregate Offering Price, Fee Rate, and Amount of Registration Fee, with footnotes that reference the prior S-11 file number and quantify the amount and aggregate price previously registered. This exhibit is where the Rule 462(b) "20%" cap is arithmetically demonstrable: the incremental aggregate offering price in EX-107 sits at or below 20% of the prior-registered aggregate.
  • EX-5.1. Legality opinion of counsel (commonly Maryland counsel for Maryland-incorporated REITs) addressed to the registrant, opining that the additional securities, when issued in accordance with the Registration Statement and the registrant's corporate proceedings, will be validly issued, fully paid and nonassessable. The opinion explicitly references the prior S-11 file number.
  • EX-8.1. Tax opinion of counsel regarding the registrant's qualification and taxation as a real estate investment trust under the Internal Revenue Code. Often includes an attached Exhibit A or schedule listing the registrant and any qualified REIT subsidiaries.
  • EX-23.1. Consent of the independent registered public accounting firm to the incorporation by reference of its audit report into the Registration Statement.

Other exhibit slots permitted by Item 601 of Regulation S-K may appear on a per-issuer basis but are uncommon; the MEF mechanism is specifically designed so most exhibits remain those previously filed under the predecessor S-11.

Included content

The dataset materializes, for every accession: the metadata.json header; the primary S-11MEF HTML document; and every non-image exhibit listed in documentFormatFiles, with its SGML wrapper preserved and its issuer-supplied filename retained. The order of documents on disk corresponds to the <SEQUENCE> integers from the submission.

Excluded or structurally separate content

Two categories of submission content are intentionally not present in the per-accession folder despite being enumerated in documentFormatFiles:

  • Image attachments. Documents whose EDGAR <TYPE> is GRAPHIC (typically .jpg files referenced by Exhibit 5.1, Exhibit 8.1, or cover-page logos and signature graphics) are excluded from the on-disk folder. Their entries remain in documentFormatFiles so that the manifest faithfully reflects the original submission, but the bytes are absent. Code traversing the disk must tolerate manifest entries with no corresponding file.
  • The full-submission .txt file. The consolidated SGML submission file (named {accession}.txt) is referenced in metadata.json -> linkToTxt and as the trailing blank-sequence "Complete submission text file" entry in documentFormatFiles, but is not copied into the per-accession folder. Equivalent content is reachable per-document through the SGML <DOCUMENT> envelopes that wrap each HTML file.

All substantive disclosure of the underlying offering itself — prospectus narrative, financial statements, risk factors, property tables, management and compensation sections, and similar — is structurally separate: it lives in the predecessor Form S-11 (and any S-11/A amendments) cited in the MEF body, and is not duplicated in the MEF record.

Coexistence of the new and prior file numbers

A defining structural feature of an S-11MEF record is the simultaneous presence of two 333- series Securities Act file numbers:

  • The new MEF file number, freshly assigned by EDGAR to the MEF submission itself, appears in metadata.json -> entities[0].fileNo and on the EDGAR filing-index page.
  • The prior effective S-11 file number, which the MEF augments under Rule 462(b), is not carried in any first-class metadata field. It appears in three places inside the document layer: in the Rule 462(b) checkbox on the cover page, in the Explanatory Note and Incorporation by Reference, and in the footnotes of EX-FILING FEES (and typically again in EX-5.1).

Joining a MEF to its predecessor S-11 therefore requires reading the body text or the EX-107/EX-5.1 exhibits; the JSON header alone is insufficient.

Historical evolution from 1996 to present

The S-11MEF mechanism dates to the SEC's 1996 adoption of Rule 462(b), and the dataset's coverage begins in April 1996, coinciding with the rule's effectiveness. Across three decades of coverage the underlying disclosure shape of the MEF has been remarkably stable — cover page, explanatory note incorporating the prior S-11 by reference, Part II Item 36 exhibit index, and signatures — but format and exhibit conventions have evolved in several material ways:

  • Submission format. The earliest S-11MEF records (mid-1996 through the late 1990s) were filed as plain-ASCII SGML submissions: a single .txt file with <DOCUMENT> envelopes whose <TEXT> bodies were unstructured ASCII rather than HTML. From the early 2000s onward, EDGAR's adoption of HTML as the standard rendition format produced submissions whose <TEXT> blocks contain full <html> documents, which is the dominant pattern across the modern portion of the dataset. The SGML <DOCUMENT> wrapper itself, with its <TYPE>, <SEQUENCE>, <FILENAME>, and <DESCRIPTION> lines, has remained unchanged across the entire coverage window.
  • Exhibit 107 / Filing Fees Disclosure. Prior to the SEC's Filing Fee Disclosure and Payment Methods Modernization rule (compliance phased in starting 2022), the Rule 457(o) registration-fee calculation appeared as a fee table on the cover page of the registration statement itself rather than as a standalone exhibit. Records filed after the compliance date carry an EX-FILING FEES document with a prescribed structured-table layout; older records embed the equivalent calculation in the cover-page fee table.
  • Counsel opinion conventions. EX-5.1 and EX-8.1 have always been customary for REIT registration statements, but the specificity of the EX-8.1 REIT tax opinion (and the practice of attaching schedules of qualified REIT subsidiaries) has expanded over time in line with evolving IRS guidance and tax-counsel diligence practice.
  • Auditor consent exhibit. EX-23.1 has been consistently present throughout the coverage window, reflecting the unchanged requirement that the predecessor S-11's audited financials, incorporated by reference, be supported by a current consent.
  • Cover-page checkbox set. The Form S-11 cover page has accumulated additional checkboxes over time (smaller-reporting-company status, emerging-growth-company status under the JOBS Act of 2012, and similar later additions). These appear on the MEF cover even though their substantive effect is largely inherited from the predecessor S-11.
  • Filing composition tooling. Late-2010s and 2020s submissions are commonly produced by EDGAR-aware composition platforms (Workiva/Wdesk and similar), which leaves identifiable comment markers and a characteristic inline-styling pattern in the HTML.

Interpretation notes

  • Incorporation by reference is total. The S-11MEF body is not self-contained. Any analytical task that needs the offering's prospectus, financial statements, or risk factors must follow the prior file number to the predecessor S-11.
  • The <TYPE> line is canonical. When classifying documents within a record, the <TYPE> line of the SGML wrapper (and the identical documentFormatFiles[].type) is the authoritative document-type label, not the filename or the visible heading on the cover page.
  • Filename heterogeneity. Filenames inside a folder are not normalized; programmatic access should resolve documents through metadata.json -> documentFormatFiles[].documentUrl rather than guessing names.
  • Manifest-versus-disk skew. documentFormatFiles always reflects the original EDGAR submission, which means GRAPHIC entries and the terminal .txt entry are listed but not present in the folder. Walkers must tolerate missing files.
  • Two file numbers. Treat entities[0].fileNo as the MEF's own file number, not as the offering's primary file number. The offering-level file number is the predecessor S-11's, which must be extracted from the document body or the EX-107/EX-5.1 exhibits.
  • Effective-date semantics. Because Rule 462(b) makes the MEF effective on filing, effectivenessDate and the date component of filedAt are identical for every record, and the signature block is dated the same day.
  • Single-filer entities. The entities array for an S-11MEF record is normally a single Filer; co-registrants are uncommon but possible in REIT structures with multiple registered entities, in which case additional entity objects appear in entities carrying the same MEF file number.

Who Files or Publishes This Dataset, and When

Each record is a short-form registration statement filed with the SEC by an issuer that already has an effective Form S-11 and wants to register additional securities of the same class in the same offering. The filer is always the same issuer that filed and obtained effectiveness of the underlying S-11. The "MEF" suffix marks a Rule 462(b) companion filing under the Securities Act of 1933 whose sole function is to expand the size of the already effective S-11 offering by up to 20 percent.

Filing population

Form S-11 is the dedicated Securities Act registration form for issuers whose business is primarily the acquisition and holding of real estate or interests in real estate. The S-11MEF population is therefore a strict subset of S-11 registrants:

Issuers with a base offering on Form S-1, Form S-3, Form F-1, or Form F-3 use the corresponding MEF form for that base form. S-11MEF is form-specific: it cannot be used unless the underlying effective registration statement is on Form S-11.

Triggering event

A Form S-11MEF is triggered by two conditions occurring together:

  1. An existing Form S-11 registration statement that has become effective under Section 8(a) of the Securities Act, and
  2. The issuer's decision (typically at pricing) to register additional securities of the same class, in an aggregate amount not exceeding 20 percent of the maximum aggregate offering price authorized by that effective S-11.

Under Rule 462(b), such a registration statement becomes effective immediately upon filing, without a Section 8(a) waiting period, acceleration request, or staff review. The S-11MEF is the form vehicle used to make a Rule 462(b) filing when the base registration is on Form S-11.

Regulatory framework

  • Section 6 of the Securities Act of 1933 establishes the registration statement mechanism and the requirement to pay fees on the maximum aggregate offering price for the additional securities registered.
  • Section 8(a) sets the default 20-day effectiveness period; Rule 462(b) carves out an exception under which a 462(b) filing is effective immediately upon filing.
  • Rule 462(b) authorizes the abbreviated companion filing, caps the additional registration at 20 percent of the base S-11's maximum aggregate offering price, and imposes the timing conditions below.
  • Rule 457 governs calculation of the registration fee on the additional maximum aggregate offering price; Rule 111 governs payment.
  • The General Instructions to Form S-11 apply by incorporation; the MEF filing does not restate substantive disclosure.

Timing and deadline logic

Rule 462(b) imposes a tight window. The S-11MEF must be filed:

  • No later than the close of business on the date of first use of the prospectus, or first sale of the additional securities, whichever applies, and
  • Within five business days of the effective date of the base S-11 to which the additional securities relate.

In practice, the filing is made on the same business day the additional securities are priced and the underwriting agreement is signed, so registration is effective before sales occur. If the five-business-day window lapses, Rule 462(b) is unavailable and the issuer must use a post-effective amendment or a new registration statement subject to ordinary Section 8(a) mechanics.

Effectiveness is automatic on EDGAR acceptance. The additional registration fee, calculated under Rule 457 and paid consistent with Rule 111, must accompany the filing; a 462(b) filing without the required fee does not satisfy the rule.

The 20 percent cap

The cap is measured against the dollar-denominated maximum aggregate offering price on the cover of the base S-11, not against share count or amount actually sold. A base S-11 authorizing $500 million permits an S-11MEF registering up to an additional $100 million of the same class. The additional securities must be of the same class as those covered by the base S-11; the MEF mechanism cannot introduce a new class or alter substantive offering terms.

Important distinctions

  • The filer is always the issuer. Underwriters and selling shareholders are not filers of the MEF, even when their interests drive the upsize.
  • Not a post-effective amendment. A Form S-11/A is a separate mechanism, can address matters beyond the 20 percent expansion, and generally does not become effective automatically.
  • Form-specific. S-11MEF excludes 462(b) companion filings by issuers whose base form is S-1, S-3, F-1, or F-3; those use the matching MEF variant.
  • Cap or window exceeded. If the additional registration exceeds 20 percent of the base maximum aggregate offering price, or the five-business-day window has passed, Rule 462(b) is unavailable and the issuer must file a new registration statement or post-effective amendment under Section 8(a).
  • S-11MEF/A amendments are uncommon and typically correct fee or cover page information; substantive disclosure remains in the base S-11.
  • Dataset coverage begins April 1996, reflecting the practical introduction of Rule 462(b) rather than a later EDGAR cut-over; there is effectively no pre-EDGAR paper population.

How This Dataset Differs From Similar Datasets or Filings

Form S-11MEF occupies a narrow niche: a Rule 462(b) abbreviated registration tied to an already-effective Form S-11, used only by real-estate-focused issuers. The forms most easily confused with it fall into three groups: the parent Form S-11 and its amendments (S-11/A), the sibling MEF forms tied to other base registrations (S-1MEF, S-3MEF, F-1MEF, F-3MEF), and the post-effectiveness prospectus filings under Rule 424.

Form S-11 (base registration statement)

S-11 is the full registration statement for REITs and other real-estate-centric issuers. It carries the entire disclosure package: property portfolio, REIT tax treatment, distribution policy, risk factors, financials, and underwriting.

S-11MEF is structurally parasitic on a prior effective S-11. It does not restate any of that content; it incorporates the S-11 by reference and adds only the additional share count, fee calculation, and issuer identifiers. S-11 is subject to staff review; S-11MEF becomes effective on filing. For substantive disclosure, go to the S-11. S-11MEF is the fee-and-quantity stub that extends it.

Form S-1MEF, S-3MEF, F-1MEF, F-3MEF (sibling MEF forms)

All five MEF forms share an identical mechanic: Rule 462(b), 20% cap on additional securities of the same class, immediate effectiveness, reference to an already-effective base registration. The only thing that varies is the base form, which determines the eligible issuer population:

  • Form S-1MEF extends an S-1, used by general operating companies that are not real-estate issuers.
  • Form S-3MEF extends an S-3, used by seasoned reporting companies meeting public-float and reporting-history thresholds. A REIT that qualifies for S-3 will almost always run S-3 plus S-3MEF instead of S-11 plus S-11MEF, so S-3MEF is the most realistic functional substitute for S-11MEF at the issuer level.
  • Form F-1MEF and Form F-3MEF are the foreign private issuer analogs of S-1MEF and S-3MEF. Foreign real-estate issuers do not generally use the S-11 track, so these never overlap with S-11MEF in filer population.

A filing's MEF flavor is fully determined by which base form was used; the choice is not discretionary. S-11MEF is therefore the unique MEF form whose issuer population is constrained to domestic real-estate businesses.

Form S-11/A (amendments to S-11)

S-11/A amends an S-11, either pre-effective (typically in response to staff comments) or post-effective (to correct, update, or supplement disclosure). Easy to confuse with S-11MEF because both extend the life of an S-11 filing, but the mechanics and purpose diverge:

  • S-11/A revises disclosure; S-11MEF revises share count.
  • S-11/A has no 20% cap; S-11MEF is hard-capped at 20% of the dollar value of securities previously registered.
  • Pre-effective S-11/A prolongs SEC review; S-11MEF bypasses review entirely and is effective on filing.
  • S-11/A is used when the original registration was inadequate or stale; S-11MEF is used when the original registration was fine but more shares are needed at pricing.

Form 424 prospectus supplements (424B1 through 424B7)

Rule 424 filings deliver the final or supplemental prospectus supplements after effectiveness, including pricing and shelf takedown details. They carry the investor-facing disclosure content. S-11MEF carries none of that: it has no prospectus, no marketing content, no pricing narrative.

The two are complementary, not substitutable. An upsized S-11 offering will typically produce both an S-11MEF (to register the extra 20%) and one or more Form 424 filings (to deliver the prospectus reflecting the upsized deal). Use 424B for what investors saw; use S-11MEF to confirm the upsize was registered.

Boundary summary

S-11MEF is uniquely defined by four constraints that no other filing type satisfies together:

  1. Issuer is eligible for Form S-11 (real-estate-focused).
  2. Filed under Rule 462(b).
  3. Registers no more than 20% additional securities of a class already registered on an effective S-11.
  4. Effective immediately upon filing, without staff review.

Sibling MEF forms share constraints 2 through 4 but differ on issuer type. S-11/A shares constraint 1 but lacks the 20% cap, the immediate effectiveness, and the quantity-extension purpose. Form 424 shares the post-effectiveness timing but is a prospectus rather than a registration. The dataset is small and disclosure-light on its own; its analytical value emerges when linked to the underlying S-11, any S-11/A history, and the related 424 prospectus filings to reconstruct an upsized real-estate offering.

Who Uses This Dataset

The dataset serves a compact set of professionals focused on REIT equity issuance, real-estate capital markets, and the legal mechanics of last-minute upsizing. Each role keys off the same compact fields — parent S-11 file number, additional share count, registration fee, effective timestamp, and EX-5.1 and EX-8.1 opinions — but applies them to distinct workflows.

REIT equity research analysts

Sector analysts covering equity and mortgage REITs use S-11MEF filings to catch last-minute offering upsizes that would otherwise be missed by tracking S-11 effectiveness alone. They read the additional share count, the registration fee (a proxy for upsize dollar size), and the underlying S-11 file number to reconcile final deal size against the original cover. Output: updated dilution math, revised FFO/AFFO and NAV-per-share estimates, and incremental-proceeds estimates for acquisition or deleveraging pipelines.

REIT ECM and syndicate desks

Equity capital markets and syndicate teams running REIT IPOs and follow-ons use the dataset as a precedent library for the 462(b) upsize playbook on real-estate deals. They look at timing relative to S-11 effectiveness, upsize size versus base deal, and registrant identity across REIT subsectors (residential, industrial, retail, healthcare, hospitality, office, self-storage, data center, mortgage). It informs sizing of the 462(b) cushion, advice to sponsors on when a top-up is warranted, and greenshoe structuring.

Capital-markets and securities lawyers

Counsel advising REIT issuers and underwriters use the dataset as a precedent file for Rule 462(b) registrations tied to Form S-11. They review the legality opinion (EX-5.1), the REIT-qualification tax opinion (EX-8.1), the recital of additional securities, and the language confirming immediate effectiveness. Workflow: drafting top-up templates, confirming incorporation by reference of the underlying S-11, and benchmarking peer REIT tax-opinion language in the upsize context.

Real-estate private equity and direct property investors

Private real-estate investment teams that compete with public REITs for assets monitor MEF filings as a leading indicator of incremental REIT equity supply. They watch issuer CIK, the dollar upsize implied by the fee, and timing relative to known acquisition pipelines to anticipate which REITs will have fresh capital for property bids. This shapes auction positioning, JV negotiations, and disposition timing to public buyers.

ECM data engineers and deal-intelligence teams

Deal-database operators ingest S-11MEF records to enrich S-11 follow-on entries with final upsize information. They parse additional shares, aggregate offering price, fee, parent S-11 file number, accession number, and effective timestamp, then attach those fields to canonical REIT deal records. Output: accurate REIT primary-supply tracking, reliable real-estate ECM league tables, and complete capital-raising telemetry for subsector dashboards.

Primary-supply and fund-flow researchers

Researchers studying REIT primary-market supply use the dataset to compute total issuance inclusive of last-minute upsizes. They aggregate share counts, dollar proceeds, and the calendar distribution of MEF filings to test whether incremental REIT supply pressures the sector index, widens REIT-to-NAV spreads, or correlates with cap-rate movements.

Filing-aggregation and data-vendor teams

Teams building EDGAR-derived data products use the dataset to maintain complete coverage of the S-11MEF form, which is low-volume but procedurally important. They standardize metadata, parse the cover and fee table, link each filing to its parent S-11 by file number, and expose additional shares as a structured field for REIT-focused dashboards and primary-market alerting.

Academic researchers in finance and securities law

Academic researchers use the dataset for empirical studies on Rule 462(b) usage in the real-estate sector. Because S-11MEF isolates the REIT slice of 462(b) filings, it supports questions on underpricing of upsized REIT offerings, determinants of last-minute expansion, underwriter-identity effects, and contrasts with operating-company practice on S-1MEF or S-3MEF. Legal and tax opinion exhibits support textual and hand-coded disclosure studies.

In-house REIT securities counsel and SEC reporting teams

In-house counsel and SEC reporting managers at REIT issuers consult peer MEF filings before preparing their own. They focus on the fee calculation, disclosure of additional registered securities, refiled auditor consent format, and cross-references to the original S-11 and prospectus supplements. The dataset supports clean execution of a 462(b) top-up on tight pricing timelines without errors that force a corrective amendment.

Underwriter operations and registration-fee specialists

Registration-fee and operations staff at REIT-active investment banks use the dataset to verify the 20% cap was respected, the SEC fee was correctly computed on the incremental amount, and the filing was made within the required post-pricing window. They check the fee table, additional aggregate offering price, base-versus-upsize ratios, and filer name to confirm procedural execution and to populate internal compliance logs of MEF top-ups the firm bookruns.

Specific Use Cases

The dataset supports a focused set of REIT and real-estate capital-markets workflows that turn on the incremental-share cap, the two-file-number structure, and the small exhibit set (EX-5.1, EX-8.1, EX-23.1, EX-FILING FEES).

Tracking REIT follow-on supply by subsector

Aggregate filedAt timestamps, entities[0].sic (predominantly 6798), and the registrant tickers array across the dataset to build a calendar of REIT 462(b) top-ups. Bucket records by REIT subsector (residential, industrial, retail, healthcare, hospitality, office, self-storage, data center, mortgage) using ticker-to-subsector mappings, then pair with the EX-FILING FEES "Maximum Aggregate Offering Price" to produce a time series of upsize dollar volume per subsector. Output feeds primary-supply dashboards and subsector-rotation models.

Computing dilution from the incremental ≤20% slice

For each MEF record, parse the EX-FILING FEES table for "Amount Registered" (additional shares) and the explanatory note for incremental dollar size, then divide by the issuer's pre-MEF share count taken from the predecessor S-11. The resulting incremental-dilution percentage and the base-versus-upsize ratio feed revised FFO/AFFO-per-share, NAV-per-share, and pro-forma leverage estimates without waiting for the 424B prospectus to settle.

Cross-referencing the original S-11 file number

Because metadata.json only carries the new MEF fileNo, the predecessor S-11 file number must be lifted from the cover-page Rule 462(b) checkbox text, the Explanatory Note, or EX-FILING FEES and EX-5.1 footnotes. Building this S-11MEF-to-S-11 join table lets deal-intelligence teams attach final upsize counts to the canonical S-11 follow-on record, complete league-table entries, and reconstruct full upsized REIT offerings (S-11, S-11/A history, S-11MEF, and 424 prospectus supplements) as a single deal object.

REIT counsel league tables from EX-5.1 and EX-8.1 signers

Parse the signature block of each EX-5.1 legality opinion to extract the law firm signing as Maryland or state counsel, and parse EX-8.1 for the REIT tax-opinion signer (often a different firm). Aggregating signer counts by year and by REIT subsector produces league tables for REIT issuer's counsel, REIT tax counsel, and combined 462(b) top-up advisory share. Useful for legal-marketing teams, lateral-hiring intelligence, and counsel-selection diligence by REIT issuers.

Aggregate Rule 462(b) usage and cap-utilization by REIT subsector

For every record, compute the ratio of EX-FILING FEES "Maximum Aggregate Offering Price" to the predecessor S-11's previously-registered aggregate (cited in the EX-107 footnotes) to measure how close each top-up runs to the 20% ceiling. Aggregated by subsector, sponsor, and underwriter, this produces a usage-intensity panel showing which REIT segments routinely max out the cushion versus which leave headroom, informing both underwriter advice on base-deal sizing and academic studies of cap-binding behavior.

Academic studies of Rule 462(b) effectiveness in REIT issuance

The dataset isolates the REIT slice of 462(b) usage from April 1996 onward, which supports empirical work on upsize-conditional underpricing, determinants of last-minute expansion, and contrasts with operating-company S-1MEF or S-3MEF practice. Researchers can combine MEF accession-level fields (effective timestamp, additional shares, fee) with hand-coded EX-8.1 REIT-qualification language and EX-23.1 auditor identity to test hypotheses about counsel quality, auditor concentration, and the marginal value of the instant-effectiveness mechanism for real-estate issuers.

Operational verification of the 20% cap and fee computation

Underwriter registration-fee desks and in-house REIT securities teams use the dataset as a precedent and self-check library. They reconcile the EX-FILING FEES "Amount of Registration Fee" against the SEC fee rate for the filing year, confirm the incremental aggregate price sits at or below 20% of the predecessor's registered aggregate, and verify that effectivenessDate equals the date component of filedAt. Peer MEFs filed by the same counsel or sponsor serve as templates for the explanatory note and signature block on tight post-pricing timelines.

Dataset Access

Dataset Index JSON API: [https://api.sec-api.io/datasets/form-s11mef-files.json](https://sec-api.io/datasets/form-s11mef-files) Returns dataset metadata (name, description, last updated timestamp, earliest sample date, total records, total size, form types, container format, and file types), the download URL for the full dataset archive, and the list of available container files with per-container size, record count, updated timestamp, and download URL. This endpoint does not require an API key and can be polled to detect which monthly containers have changed during the most recent refresh, so only updated containers need to be re-downloaded.

Example
1 {
2 "datasetId": "1f13365b-9ae0-6a11-a83d-49775e6618cf",
3 "datasetDownloadUrl": "https://api.sec-api.io/datasets/form-s11mef-files.zip",
4 "name": "Form S-11MEF Files Dataset",
5 "updatedAt": "2026-04-15T18:26:07.392Z",
6 "earliestSampleDate": "1996-04-01",
7 "totalRecords": 417,
8 "totalSize": 1443535,
9 "formTypes": ["S-11MEF"],
10 "containerFormat": "ZIP",
11 "fileTypes": ["TXT", "JSON", "HTML"],
12 "containers": [
13 {
14 "downloadUrl": "https://api.sec-api.io/datasets/form-s11mef-files/2026/2026-03.zip",
15 "key": "2026/2026-03.zip",
16 "size": 13818783,
17 "records": 12,
18 "updatedAt": "2026-04-15T18:26:07.392Z"
19 }
20 ]
21 }

Download Entire Dataset: [https://api.sec-api.io/datasets/form-s11mef-files.zip](https://sec-api.io/datasets/form-s11mef-files)?token=YOUR_API_KEY Downloads the complete Form S-11MEF Files dataset as a single ZIP archive covering all filings from April 1996 to present. This endpoint requires an API key.

Download Single Container: https://api.sec-api.io/datasets/form-s11mef-files/2026/2026-03.zip?token=YOUR_API_KEY Downloads one monthly container ZIP instead of the full dataset, which is useful for incremental syncs based on the updatedAt timestamps returned by the index API. This endpoint requires an API key.

Frequently Asked Questions

What form does this dataset cover?

The dataset covers Form S-11MEF, a short-form registration statement filed under Rule 462(b) of the Securities Act of 1933 to register up to an additional 20 percent of securities for an offering already registered on a previously effective Form S-11. The MEF becomes effective immediately on filing, without staff review or a Section 8(a) waiting period.

What does one record in this dataset represent?

One record is a single EDGAR submission of Form S-11MEF, identified by its 18-digit accession number. On disk it is a folder containing one metadata.json header plus one HTML file per non-image document in the original submission — typically the primary S-11MEF document, EX-FILING FEES (Exhibit 107), EX-5.1, EX-8.1, and EX-23.1.

Who is required to file Form S-11MEF?

The filer is always the issuer that already obtained effectiveness on the underlying Form S-11, which restricts the population to REITs (equity, mortgage, and hybrid), real estate operating companies, real estate limited partnerships, and other issuers whose business is primarily the acquisition and holding of real estate. Underwriters and selling shareholders never file the MEF themselves.

When must an S-11MEF be filed?

Under Rule 462(b) the MEF must be filed no later than the close of business on the date of first use of the prospectus or first sale of the additional securities, and within five business days of the effective date of the base S-11. In practice it is filed on the same business day the additional securities are priced and the underwriting agreement is signed.

What time period does the dataset cover, and in what file format?

Coverage runs from April 1996 — the effective date of Rule 462(b) — to the present. The dataset is distributed as monthly ZIP containers organized as {year}/{year}-{month}.zip, and the per-record file types are TXT, JSON, and HTML.

How does S-11MEF differ from S-11/A and from sibling MEF forms?

S-11/A amends the underlying S-11 to revise disclosure, has no 20 percent cap, and does not become effective automatically. The sibling MEF forms (S-1MEF, S-3MEF, F-1MEF, F-3MEF) share the same Rule 462(b) mechanic, 20 percent cap, and immediate-effectiveness behavior, but differ on the base form and therefore on the eligible issuer population; S-11MEF is the unique MEF flavor whose filers are constrained to domestic real-estate issuers.

Why does each record reference two different file numbers?

Every S-11MEF carries a freshly assigned MEF file number in metadata.json -> entities[0].fileNo and also references the predecessor S-11 file number that it augments. The prior S-11 number is not in any first-class JSON field; it appears in the Rule 462(b) checkbox on the cover page, in the Explanatory Note and Incorporation by Reference, and in the footnotes of EX-FILING FEES and EX-5.1, so joining a MEF to its underlying S-11 requires parsing the document layer.