Document and Entity Information	Total
Prospectus:
Document Type	485BPOS
Document Period End Date	May 31, 2021
Registrant Name	BNY Mellon California AMT-Free Municipal Bond Fund, Inc.
Entity Central Index Key	0000720064
Entity Inv Company Type	N-1A
Amendment Flag	false
Document Creation Date	Sep. 22, 2021
Document Effective Date	Sep. 30, 2021
Prospectus Date	Sep. 30, 2021
BNY Mellon California AMT-Free Municipal Bond Fund, Inc. \| Class Z
Prospectus:
Trading Symbol	DRCAX
BNY Mellon California AMT-Free Municipal Bond Fund, Inc. \| Class C
Prospectus:
Trading Symbol	DCACX
BNY Mellon California AMT-Free Municipal Bond Fund, Inc. \| Class A
Prospectus:
Trading Symbol	DCAAX
BNY Mellon California AMT-Free Municipal Bond Fund, Inc. \| Class I
Prospectus:
Trading Symbol	DCMIX
BNY Mellon California AMT-Free Municipal Bond Fund, Inc. \| Class Y
Prospectus:
Trading Symbol	DCAYX

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