Affidavit of Indigency materials from the the Mass Courts website [1]: 

The following forms and related documents used to request waiver, substitution or payment of court fees and court costs by the Commonwealth pursuant to G. L. c. 261, § 27B [2]. can be found on the Mass courts website: 

• Poverty Threshold Guidelines
• Affidavit of Indigency 
• Supplement to Affidavit of Indigency 
• Instructions for Users  
• Inmate's Affidavit of Indigency
• Courts Determination Regarding Fees and Costs

Attached is the March 25, 2003 memo that Chief Justice Marshall  (SJC) issued along with the forms for requesting a waiver, substitution, or payment by the Commonwealth of court fees and costs.