Annual report pursuant to Section 13 and 15(d)

Cover Page

Cover Page - USD ($)
12 Months Ended
Sep. 30, 2022
Nov. 14, 2022
Mar. 31, 2022
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Sep. 30, 2022    
Current Fiscal Year End Date --09-30    
Document Transition Report false    
Entity File Number 1-12997    
Entity Registrant Name Maximus, Inc.    
Entity Incorporation, State or Country Code VA    
Entity Tax Identification Number 54-1000588    
Entity Address, Address Line One 1600 Tysons Boulevard    
Entity Address, City or Town McLean    
Entity Address, State or Province VA    
Entity Address, Postal Zip Code 22102    
City Area Code 703    
Local Phone Number 251-8500    
Title of 12(b) Security Common Stock, no par value    
Trading Symbol MMS    
Security Exchange Name NYSE    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Large Accelerated Filer    
Entity Small Reporting Company false    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag true    
Entity Shell Company false    
Entity Public Float     $ 4,577,509,491
Entity Common Stock, Shares Outstanding   60,773,258  
Documents Incorporated by Reference Portions of the registrant's definitive Proxy Statement for its 2023 Annual Meeting of Shareholders to be held on March 14, 2023, which definitive Proxy Statement will be filed with the Securities and Exchange Commission not later than 120 days after the end of the registrant's fiscal year, are incorporated by reference into Part III of this Form 10-K.    
Entity Central Index Key 0001032220    
Document Fiscal Year Focus 2022    
Document Fiscal Period Focus FY    
Amendment Flag false