# EDGAR Filing Document

**Accession Number:** 0001459839
**File Stem:** 0001459839-26-000040
**Filing Date:** 2026-2
**Character Count:** 25646
**Document Hash:** 91faaca5805820b425768a9bc00badc7
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001459839-26-000040.hdr.sgml**: 20260224

**ACCESSION NUMBER**: 0001459839-26-000040

**CONFORMED SUBMISSION TYPE**: S-8

**PUBLIC DOCUMENT COUNT**: 15

**FILED AS OF DATE**: 20260224

**DATE AS OF CHANGE**: 20260224

**EFFECTIVENESS DATE**: 20260224

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** SI-BONE, Inc.
- **CENTRAL INDEX KEY:** 0001459839
- **STANDARD INDUSTRIAL CLASSIFICATION:** SURGICAL & MEDICAL INSTRUMENTS & APPARATUS [3841]
- **ORGANIZATION NAME:** 08 Industrial Applications and Services
- **EIN:** 262216351
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** S-8
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 333-293689
- **FILM NUMBER:** 26672203

**BUSINESS ADDRESS:**
- **STREET 1:** 471 EL CAMINO REAL, SUITE 101
- **CITY:** SANTA CLARA
- **STATE:** CA
- **ZIP:** 95050
- **BUSINESS PHONE:** 4082070700

**MAIL ADDRESS:**
- **STREET 1:** 471 EL CAMINO REAL, SUITE 101
- **CITY:** SANTA CLARA
- **STATE:** CA
- **ZIP:** 95050

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** SI-Bone Inc.
- **DATE OF NAME CHANGE:** 20090326

**As filed with the U.S. Securities and Exchange Commission on February 24, 2026**

**Registration No. 333-**

_____________________________________

**UNITED STATES**

**SECURITIES AND EXCHANGE COMMISSION**

Washington, D.C. 20549

_____________________________________

**FORM S-8**

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

_____________________________________

**SI-BONE, Inc.**

(Exact name of Registrant as specified in its charter)

---

| | |
|:---|:---|
| **Delaware** | **26-2216351** |
| (State or other jurisdiction of Incorporation or organization) | (I.R.S. Employer Identification No.) |

---

**471 El Camino Real, Suite 101**

**Santa Clara, California 95050**

**(408) 207-0700**

(Address of principal executive offices) (Zip code)

_____________________________________

**SI-BONE, Inc. 2018 Equity Incentive Plan**

**SI-BONE, Inc. 2018 Employee Stock Purchase Plan**

(Full titles of the plans)

_____________________________________

**Anshul Maheshwari**

**Chief Operating Officer & Chief Financial Officer**

**SI-BONE, Inc.**

**471 El Camino Real, Suite 101**

**Santa Clara, California 95050**

**(408) 207-0700**

(Name and address of agent for service) (Telephone number, including area code, of agent for service)

Copies to:

**Matthew B. Hemington**

**Kate Nichols**

**Allison Pang**

**Cooley LLP**

**3175 Hanover Street**

**Palo Alto, California 94304**

**(650) 843-5000**

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of "large accelerated filer," "accelerated filer," "smaller reporting company," and "emerging growth company" in Rule 12b-2 of the Exchange Act.

---

| | | | |
|:---|:---|:---|:---|
| Large accelerated filer | ⌧ | Accelerated filer | □ |
| Non-accelerated filer | □ | Smaller reporting company | □ |
| | | Emerging growth company | □ |

---

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ☐

------

**EXPLANATORY NOTE**

Pursuant to General Instruction E of Form S-8, SI-BONE, Inc. (the "***Registrant***") is filing this Registration Statement for the purpose of registering (a) an additional 2,182,356 shares of its common stock, issuable to eligible persons under its 2018 Equity Incentive Plan (the "2018 Plan"), which common stock is in addition to the shares of common stock previously registered on the Registrant's Form S-8 registration statements filed on October 19, 2018 (File No. 333-227907), March 22, 2019 (File No. 333-230473), March 11, 2020 (File No. 333-237091), March 10, 2021 (File No. 333-254086), March 1, 2022 (File No. 333-263189), March 2, 2023 (File No. 333-270230), February 27, 2024 (File No. 333-277402), and February 25, 2025 (File No. 333-285206) (the "***Prior Forms S-8***") and (b) an additional 436,471 shares of its common stock, issuable to eligible persons under its 2018 Employee Stock Purchase Plan (the "2018 ESPP"), which common stock is in addition to the shares of common stock previously registered on the Prior Forms S-8. The contents of the Prior Forms S-8 are incorporated by reference in this Registration Statement.

**PART II** 

**ITEM 3.**&nbsp;&nbsp;&nbsp;&nbsp;**INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE**

The following documents filed by the Registrant with the Securities and Exchange Commission (the "***SEC***") are incorporated by reference into this Registration Statement:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;**(a)**&nbsp;&nbsp;&nbsp;&nbsp;The contents of the earlier registration statements on Form S-8 relating to the 2018 Plan and 2018 ESPP, filed with the SEC on <u>[October 19, 2018](https://www.sec.gov/Archives/edgar/data/1459839/000119312518303158/d635537ds8.htm)</u> (File No. 333-227907), <u>[March 22, 2019](https://www.sec.gov/Archives/edgar/data/1459839/000145983919000015/s-8evergreen2019.htm)</u> (File No. 333-230473), <u>[March 11, 2020](https://www.sec.gov/Archives/edgar/data/1459839/000145983920000032/s-8evergreen2020.htm)</u> (File No. 333-237091), <u>[March 10, 2021](https://www.sec.gov/Archives/edgar/data/1459839/000145983921000015/s-8evergreenjanuary2021.htm)</u> (File No. 333-254086), <u>[March 1, 2022](https://www.sec.gov/Archives/edgar/data/1459839/000145983922000020/s-8evergreenjanuary2022.htm)</u> (File No. 333-263189), <u>[March 2, 2023](https://www.sec.gov/Archives/edgar/data/1459839/000145983923000022/s-8evergreenjanuary2023.htm)</u> (File No. 333-270230), <u>[February 27, 2024](https://www.sec.gov/Archives/edgar/data/1459839/000145983924000017/s-8evergreenfebruary27.htm)</u> (File No. 333-277402), and <u>[February 25, 2025](https://www.sec.gov/Archives/edgar/data/1459839/000145983925000038/s-8evergreenfebruary25_fy25.htm)</u> (File No. 333-285206).

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;**(b)**&nbsp;&nbsp;&nbsp;&nbsp;The Registrant's Annual Report on Form 10-K for the year ended December 31, 2025, filed with the SEC on <u>[February 24, 2026](https://www.sec.gov/ix?doc=/Archives/edgar/data/0001459839/000145983926000036/sibn-20251231.htm)</u>.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;**(c)**&nbsp;&nbsp;&nbsp;&nbsp;The description of the Registrant's Common Stock which is contained in a registration statement on <u>[Form 8-A filed on October 11, 2018](https://www.sec.gov/Archives/edgar/data/1459839/000119312518297571/d486750d8a12b.htm)</u> (File No. 001-38701) under the Exchange Act of 1934, as amended (the "***Exchange Act***"), including any amendment or report filed for the purpose of updating such description, including the Description of SI-BONE, Inc. Common Stock filed as Exhibit 4.3 to the Registrant's Quarterly Report on Form 10-Q filed with the SEC on May 5, 2020.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;**(d)**&nbsp;&nbsp;&nbsp;&nbsp;All other reports and documents subsequently filed by the Registrant pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act (other than Current Reports furnished under Item 2.02 or Item 7.01 of Form 8-K and exhibits furnished on such form that relate to such items) on or after the date of this Registration Statement and prior to the filing of a post-effective amendment to this Registration Statement which indicates that all securities offered have been sold or which deregisters all securities then remaining unsold, shall be deemed to be incorporated by reference herein and to be a part of this Registration Statement from the date of the filing of such reports and documents. Any statement contained in a document incorporated or deemed to be incorporated by reference herein shall be deemed to be modified or superseded for purposes of this Registration Statement to the extent that a statement contained herein or in any subsequently filed document that also is deemed to be incorporated by reference herein modifies or supersedes such statement. Any such statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this Registration Statement.

------

**ITEM 8.**&nbsp;&nbsp;&nbsp;&nbsp;**EXHIBITS**

The exhibits to this Registration Statement are listed below.

---

| | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|
| | | **Incorporated by Reference** | **Incorporated by Reference** | **Incorporated by Reference** | **Incorporated by Reference** | |
|<br>**Exhibit<br>Number** |<br>**Description** | **Schedule<br>Form** | **File Number** | **Exhibit** | **Filed On** |<br>**Filed Herewith** |
| 4.1 | <u>[Amended and Restated Certificate of Incorporation](https://www.sec.gov/Archives/edgar/data/1459839/000119312518303020/d641574dex31.htm)</u> | 8-K | 001-38701 | 3.1 | October 19, 2018 |  |
| 4.2 | <u>[Amendment to Amended and Restated Certificate of Incorporation](https://www.sec.gov/ix?doc=/Archives/edgar/data/0001459839/000145983924000048/sibn-20240625.htm)</u> | 8-K | 001-38701 | 3.1 | June 26, 2024 |  |
| 4.3 | <u>[Second Amended and Restated Bylaws](https://www.sec.gov/Archives/edgar/data/1459839/000145983923000095/secondamendedandrestatedby.htm)</u> | 8-K | 001-38701 | 3.1 | September 20, 2023 |  |
| 4.4 | <u>[Form of Registrant's Common Stock Certificate.](https://www.sec.gov/Archives/edgar/data/1459839/000119312518293978/d452987dex41.htm)</u> | S-1/A | 333-227445 | 4.1 | October 5, 2018 |  |
| 5.1 | <u>[Opinion of Cooley LLP.](exhibit51-sx8cooleysopinion.htm)</u> |  |  |  |  | x |
| 23.1 | <u>[Consent of PricewaterhouseCoopers LLP, Independent Registered Public Accounting Firm.](exhibit231-s8consent.htm)</u> |  |  |  |  | x |
| 24.1 | <u>[Power of Attorney (included on the signature page of this Form S-8).](#i1fe9e1d8d8f4440eb334ada31f8187d0_4)</u> |  |  |  |  | x |
| 99.1 | <u>[2018 Equity Incentive Plan.](https://www.sec.gov/Archives/edgar/data/1459839/000119312518293978/d452987dex103.htm)</u> | S-1/A | 333-227445 | 10.3 | October 5, 2018 |  |
| 99.2 | <u>[Forms of Stock Option Grant Notice, Option Agreement and Notice of Exercise under the 2018 Equity Incentive Plan.](https://www.sec.gov/Archives/edgar/data/1459839/000119312518293978/d452987dex104.htm)</u> | S-1/A | 333-227445 | 10.4 | October 5, 2018 |  |
| 99.3 | <u>[Forms of Restricted Stock Unit Grant Notice and Restricted Stock Unit Award Agreement under the 2018 Equity Incentive Plan.](https://www.sec.gov/Archives/edgar/data/1459839/000119312518293978/d452987dex105.htm)</u> | S-1/A | 333-227445 | 10.5 | October 5, 2018 |  |
| 99.4 | <u>[2018 Employee Stock Purchase Plan.](https://www.sec.gov/Archives/edgar/data/1459839/000119312518293978/d452987dex106.htm)</u> | S-1/A | 333-227445 | 10.6 | October 5, 2018 |  |
| 99.5 | <u>[Form of Performance-Based Restricted Stock Unit Agreement](https://www.sec.gov/Archives/edgar/data/1459839/000145983922000006/si-bonexformofprsugrantp.htm)</u> | 8-K | 001-38701 | 10.1 | January 10, 2022 |  |
| 99.6 | <u>[Form of Financial Performance-Based Restricted Stock Unit Agreement](https://www.sec.gov/Archives/edgar/data/1459839/000145983925000036/sibn-ex1029_formoffinancia.htm)</u> | 10-K | 001-38707 | 10.29 | February 25, 2025 |  |
| 107 | <u>[Filing Fee Table](exfilingfees.htm)</u> |  |  |  |  | x |

---

------

**SIGNATURES**

Pursuant to the requirements of the Securities Act of 1933, as amended, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Santa Clara, State of California, on this 24th day of February 2026.

---

| | |
|:---|:---|
| **SI-BONE, Inc.** | **SI-BONE, Inc.** |
| By: | /s/ Laura A. Francis |
|  | Laura A. Francis |
|  | Chief Executive Officer |

---

------

**POWER OF ATTORNEY**

**Know All Persons By These Presents**, that each person whose signature appears below constitutes and appoints Laura A. Francis, and Michael A. Pisetsky, each of them, as his or her true and lawful attorneys-in-fact and agents, each with the full power of substitution, for him or her and in their name, place or stead, in any and all capacities, to sign any and all amendments to this Registration Statement (including post-effective amendments), and to sign any registration statement for the same offering covered by this Registration Statement that is to be effective upon filing pursuant to Rule 462(b) promulgated under the Securities Act, and all post-effective amendments thereto, and to file the same, with all exhibits thereto and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing requisite and necessary to be done in connection therewith, as fully to all intents and purposes as he or she might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents or any of them, or his, her or their substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act, this Registration Statement has been signed by the following persons in the capacities and on the dates indicated.

---

| | | |
|:---|:---|:---|
| **Signature** | **Title** | **Date** |
| /s/ Laura A. Francis | Chief Executive Officer and Director<br>(*Duly Authorized Officer and Principal Executive Officer*)  | February 24, 2026 |
| Laura A. Francis | Chief Executive Officer and Director<br>(*Duly Authorized Officer and Principal Executive Officer*)  | February 24, 2026 |
| /s/ Anshul Maheshwari | Chief Operating Officer & Chief Financial Officer<br>*(Principal Financial and Accounting Officer)* | February 24, 2026 |
| Anshul Maheshwari | Chief Operating Officer & Chief Financial Officer<br>*(Principal Financial and Accounting Officer)* | February 24, 2026 |
| /s/ Timothy E. Davis, Jr. | Director | February 24, 2026 |
| Timothy E. Davis, Jr. | Director | February 24, 2026 |
| /s/ Jeffrey W. Dunn | Chairman of the Board of Directors | February 24, 2026 |
| Jeffrey W. Dunn | Chairman of the Board of Directors | February 24, 2026 |
| /s/ John G. Freund, M.D. | Director | February 24, 2026 |
| John G. Freund, M.D. | Director | February 24, 2026 |
| /s/ Jeryl L. Hilleman | Director | February 24, 2026 |
| Jeryl L. Hilleman | Director | February 24, 2026 |
| /s/ Gregory K. Hinckley | Director | February 24, 2026 |
| Gregory K. Hinckley | Director | February 24, 2026 |
| /s/ Mika Nishimura | Director | February 24, 2026 |
| Mika Nishimura | Director | February 24, 2026 |
| /s/ Thomas A. West | Director | February 24, 2026 |
| Thomas A. West | Director | February 24, 2026 |

---

## Ex-Filing

?xml version='1.0' encoding='ASCII'? EX-FILING FEES

---

| |
|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Calculation of Filing Fee Tables**  |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **S-8**  |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **SI-BONE, Inc.**  |

---

---

| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
| | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Security Type**  | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Security Class Title**  | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Fee Calculation Rule**  | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Amount Registered**  | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Proposed Maximum Offering Price Per Unit**  | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Maximum Aggregate Offering Price**  | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Fee Rate**  | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Amount of Registration Fee**  |
| 1 | Equity | Common Stock, $0.0001 par value per share, SI-BONE, Inc. 2018 Equity Incentive Plan | Other | 2182356 | $15.62 | $34088400.72 | 0.0001381 | $4707.61 |
| 2 | Equity | Common Stock, $0.0001 par value per share, SI-BONE, Inc. 2018 Employee Stock Purchase Plan | Other | 436471 | $13.28 | $5796334.88 | 0.0001381 | $800.47 |
| Total Offering Amounts: | Total Offering Amounts: | Total Offering Amounts: | Total Offering Amounts: | Total Offering Amounts: |  | $39884735.60  |  | $5508.08  |
| Total Fee Offsets:  | Total Fee Offsets:  | Total Fee Offsets:  | Total Fee Offsets:  | Total Fee Offsets:  |  |  |  | $0.00  |
| Net Fee Due:  | Net Fee Due:  | Net Fee Due:  | Net Fee Due:  | Net Fee Due:  |  |  |  | $5508.08  |

---

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Offering Note** <br>

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <sup>1</sup> Pursuant to Rule 416(a) of the Securities Act of 1933, as amended (the "Securities Act"), this Registration Statement also covers any additional securities that may be offered or become issuable under the SI-BONE, Inc. 2018 Equity Incentive Plan in connection with any stock split, stock dividend, recapitalization or any other similar transaction effected without receipt of consideration, which results in an increase in the number of the Registrant's outstanding shares of Common Stock. Estimated in accordance with Rules 457(c) and 457(h) under the Securities Act, solely for the purposes of calculating the registration fee, based upon $15.62 per share, which is the average of the high and low selling prices of the Registrant's Common Stock as reported on the Nasdaq Global Market on February 19, 2026.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <sup>2</sup> Pursuant to Rule 416(a) of the Securities Act, this Registration Statement also covers any additional securities that may be offered or become issuable under the SI-Bone, Inc. 2018 Employee Stock Purchase Plan (the "2018 ESPP") in connection with any stock split, stock dividend, recapitalization or any other similar transaction effected without receipt of consideration, which results in an increase in the number of the Registrant's outstanding shares of Common Stock. Estimated in accordance with Rules 457(c) and 457(h) under the Securities Act solely for the purpose of calculating the registration fee, based upon $15.62 per share, which is the average of the high and low selling prices of the Registrant's Common Stock as reported on the Nasdaq Global Market on February 19, 2026, multiplied by 85%, which is the percentage of the price per share applicable to purchases under the 2018 ESPP.

---

| | |
|:---|:---|
| | |
| **Rule 457(p)** | **Rule 457(p)** |
| Fee Offset Claims | N/A |
| Fee Offset Sources | N/A |

---

## Exhibit 5.1

**Exhibit 5.1**

![image_0a.jpg](image_0a.jpg)

Kate Nichols

T: +1 650 843 5877

knichols@cooley.com

February 24, 2026

SI-BONE, Inc.

471 El Camino Real, Suite 101

Santa Clara, CA 95050

**Re:&nbsp;&nbsp;&nbsp;&nbsp;Registration on Form S-8&nbsp;&nbsp;&nbsp;&nbsp;**

Ladies and Gentlemen:

We have acted as counsel to SI-BONE, Inc., a Delaware corporation (the "***Company***"), in connection with the filing by the Company of a Registration Statement on Form S-8 (the "***Registration Statement***") with the Securities and Exchange Commission (the "***Commission***") covering the offering of up to 2,618,827 shares (the "***Shares***") of the Company's common stock, par value $0.0001 per share ("***Common Stock***"), consisting of (a) 2,182,356 shares of Common Stock issuable pursuant to the Company's 2018 Equity Incentive Plan (the "***EIP***"), and (b) 436,471 shares of Common Stock issuable pursuant to the Company's 2018 Employee Stock Purchase Plan (together with the EIP, the "***Plans***").

In connection with this opinion, we have examined and relied upon (a) the Registration Statement and the related prospectuses, (b) the Plans, (c) the Company's certificate of incorporation and bylaws, each as currently in effect, and (d) such other records, documents, opinions, certificates, memoranda, and instruments as in our judgment are necessary or appropriate to enable us to render the opinion expressed below. We have assumed the genuineness of all signatures, the authenticity of all documents submitted to us as originals, the conformity to originals of all documents submitted to us as copies, the accuracy, completeness and authenticity of certificates of public officials, and the due authorization, execution and delivery of all documents by all persons other than the Company. As to certain factual matters, we have relied upon a certificate of an officer of the Company and have not independently verified such matters.

Our opinion is expressed only with respect to the General Corporation Law of the State of Delaware. We express no opinion to the extent that any other laws are applicable to the subject matter hereof and express no opinion and provide no assurance as to compliance with any federal or state securities law, rule or regulation.

On the basis of the foregoing, and in reliance thereon, we are of the opinion that the Shares, when sold and issued in accordance with the Plans, the Registration Statement and the related prospectuses, will be validly issued, fully paid, and nonassessable (except as to shares issued pursuant to deferred payment arrangements, which will be fully paid and nonassessable when such deferred payments are made in full).

This opinion is limited to the matters expressly set forth in this letter, and no opinion should be implied, or may be inferred, beyond the matters expressly stated. This opinion speaks only as to law and facts in effect or existing as of the date hereof, and we have no obligation or responsibility to update or supplement this opinion to reflect any facts or circumstances that may hereafter come to our attention or any changes in law that may hereafter occur.

Cooley LLP 3175 Hanover Street Palo Alto, CA 94304-1130

t: (650) 843-5000 f: (650) 849-7400 cooley.com

------

We consent to the filing of this opinion as an exhibit to the Registration Statement. In giving such consent, we do not thereby admit that we are in the category of persons whose consent is required under Section 7 of the Securities Act of 1933, as amended, or the rules and regulations of the Commission thereunder.

Sincerely,

**Cooley LLP**

---

| | |
|:---|:---|
| **By:** | /s/ Kate Nichols |
|  | **Kate Nichols** |

---

Cooley LLP 3175 Hanover Street Palo Alto, CA 94304-1130

t: (650) 843-5000 f: (650) 849-7400 cooley.com

## Exhibit 23.1

**Exhibit 23.1**

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We hereby consent to the incorporation by reference in this Registration Statement on Form S-8 of SI-BONE, Inc. of our report dated February 24, 2026 relating to the financial statements and the effectiveness of internal control over financial reporting, which appears in SI-BONE, Inc.'s Annual Report on Form 10-K for the year ended December 31, 2025. We also consent to the reference to us under the heading "Experts" in such Registration Statement.

/s/ PricewaterhouseCoopers LLP<br>San Jose, California <br>February 24, 2026

<br>