<SEC-DOCUMENT>0001562180-19-004347.txt : 20190819
<SEC-HEADER>0001562180-19-004347.hdr.sgml : 20190819
<ACCEPTANCE-DATETIME>20190819161018
ACCESSION NUMBER:		0001562180-19-004347
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20190816
FILED AS OF DATE:		20190819
DATE AS OF CHANGE:		20190819

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			DUNN JEFFREY W
		CENTRAL INDEX KEY:			0001035986

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-38701
		FILM NUMBER:		191036571

	MAIL ADDRESS:	
		STREET 1:		C/O SI-BONE, INC.
		STREET 2:		471 EL CAMINO REAL, SUITE 101
		CITY:			SANTA CLARA
		STATE:			CA
		ZIP:			95050

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SI-BONE, Inc.
		CENTRAL INDEX KEY:			0001459839
		STANDARD INDUSTRIAL CLASSIFICATION:	SURGICAL & MEDICAL INSTRUMENTS & APPARATUS [3841]
		IRS NUMBER:				262216351
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	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
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primarydocument.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-08-16</periodOfReport>

    <notSubjectToSection16>false</notSubjectToSection16>

    <issuer>
        <issuerCik>0001459839</issuerCik>
        <issuerName>SI-BONE, Inc.</issuerName>
        <issuerTradingSymbol>SIBN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001035986</rptOwnerCik>
            <rptOwnerName>DUNN JEFFREY W</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SI-BONE, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>471 EL CAMINO REAL, SUITE 101</rptOwnerStreet2>
            <rptOwnerCity>SANTA CLARA</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95050</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>true</isDirector>
            <isOfficer>true</isOfficer>
            <isTenPercentOwner>false</isTenPercentOwner>
            <isOther>false</isOther>
            <officerTitle>Chairman, President &amp; CEO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2019-08-16</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>false</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>40000.00</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>19.6435</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>507540.00</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>by Trust</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>99997.00</value>
                    <footnoteId id="F4"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The sale reported on this Form 4 was effected pursuant to a 10b5-1 trading plan.</footnote>
        <footnote id="F2">The price reported in column 4 is a weighted-average price. The shares were sold in multiple transactions ranging from $19.00 to $20.00, inclusive. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer, or the Staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.</footnote>
        <footnote id="F3">Shares held by The Jeffrey W. Dunn Living Trust Dated May 17, 2012.</footnote>
        <footnote id="F4">Includes 92,920 shares issuable on settlement of restricted stock units granted to the Reporting Person. Each restricted stock unit represents a contingent right to receive on shares of the Issuer's common stock.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Michael A. Pisetsky, Attorney-in-Fact for Jeffrey W. Dunn</signatureName>
        <signatureDate>2019-08-19</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
