AIA document families: A-, B-, C-, and G-series by relationship governed

One-line orientation

AIA document letters group forms by the relationship or project function they cover. Start by matching each series to its main use.

Key points

• A-series — commonly Owner–Contractor:
• Covers the construction contract between owner and contractor.
• Example: A101-2017 (stipulated-sum owner–contractor agreement).
• A201-2017 General Conditions of the Contract for Construction is the foundational rules document; it is incorporated by reference into A101 and defines the rights, duties, and procedures for all parties during construction (owner, contractor, architect).
• A201 defines what the contract documents are, the architect’s CA role, change-order procedures, and dispute resolution (architect as initial decision maker).
• B-series — commonly Owner–Architect:
• Covers the professional services agreement between owner and architect.
• Standard form: B101-2017. Supplemental Services are designated in the Section 4.1 table (B2xx exhibit documents describe each scope); Additional Services that arise later fall under Section 4.2.
• C-series — Other project agreements: C-series documents cover architect-consultant agreements and other project agreements. C401 is the standard architect-consultant agreement.
• A common use is the agreement between the architect and specialized consultants (structural, MEP, etc.).
• Standard form: C401-2017. C401 incorporates and flows down the prime B101 terms.
• G-series — Contract Administration Forms:
  • Standardized forms used during project administration: pay application certificates, field reports, change orders, submittals logs, etc.
  • These are tools for executing the contract, not agreements themselves.

AIA document families — who contracts with whom

The series letter points to a main relationship or project function; the document number identifies the form.

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Do not treat the Architect as a signatory to A201. A201 is the General Conditions document for the Owner–Contractor agreement and also describes the Architect’s construction-phase role.

A = Owner–Contractor · B = Owner–Architect · C = other project agreements, including Architect–Consultant

Confusions / comparison

Series	Parties	Relationship	Key example documents
A-series	Owner ↔ Contractor	Construction contract	A101 (stipulated sum), A133 (CMc/GMP), A201 General Conditions
B-series	Owner ↔ Architect	Professional services	B101 (standard O–A agreement), B2xx (supplemental service exhibits)
C-series	Varies by form	Other project agreements, including Architect–Consultant	C401 (standard architect–consultant agreement)
G-series	(All parties)	Contract admin forms	Pay app certificates, field reports, change orders

Related

→ pp-aia-b101-owner-architect (this module): anatomy of B101 in detail · pp-aia-c401-architect-consultant (this module): how C401 flows down from B101 · pp-basic-vs-additional-services (this module): where supplemental and additional services live in the B-series.