Source & Authority Information
- •FAR Subpart 4.10 - Uniform Use of Line Items(accessed 2026-01-15)
What Are Contract Line Item Numbers
CLIN Numbering and Hierarchy
- Base CLINs (0001, 0002, 0003): Four-digit numbers identifying major contract line items. Each base CLIN represents a distinct category of work, supply, or service with its own pricing and potentially its own contract type.
- SubCLINs (0001AA, 0001AB, 0001AC): Six-character extensions subdividing base CLINs into more granular elements. SubCLINs commonly represent different performance periods, different locations, or specific deliverables within a CLIN category.
- Option CLINs: Line items for work the government may exercise at its discretion. Option CLINs typically appear as distinct base CLINs or as optional SubCLINs under base CLINs, clearly identified as options rather than base requirements.
- Informational CLINs: Line items providing information without obligating funds, such as total estimated amounts for indefinite quantity contracts or ceiling values. These CLINs establish visibility without commitment.
- Exhibit Line Items: Additional identifiers used in complex procurements with extensive item structures, often appearing in supply contracts with many individual products organized under broader CLIN categories.
Types of CLINs by Contract Type
Developing CLIN Pricing Strategies
- 1Analyze the solicitation CLIN structure
Thoroughly review how the solicitation organizes requirements into CLINs. Map each CLIN to corresponding statement of work tasks. Understand what deliverables, services, or supplies each CLIN covers. Identify relationships between CLINs and option structures.
- 2Develop bottom-up cost estimates
Estimate costs for each CLIN based on the specific work, staffing, materials, and resources required. Do not simply allocate total costs across CLINs proportionally—each CLIN should reflect its actual resource requirements and complexity.
- 3Analyze evaluation approach
Understand how the government will evaluate CLIN pricing. Determine whether evaluation assesses total price only or examines individual CLIN pricing for reasonableness. Assessment approach affects how you can allocate pricing across CLINs.
- 4Consider competitive dynamics
Different CLINs may favor different competitors based on their strengths. Position pricing strategically to compete effectively on CLINs where you have advantages while remaining competitive overall.
- 5Validate pricing balance
Review final pricing to ensure CLINs are priced consistently with their scope and risk. Identify and correct any unbalanced pricing that evaluators might question. Ensure pricing is defensible if questioned during evaluation.
Avoiding CLIN Pricing Problems
- Avoid front-loading that increases government cash flow costs in early periods while reducing later period pricing below sustainable levels.
- Do not understate base period pricing to win competitions with intentions to recover margins in option years—this creates both evaluation and performance risks.
- Ensure pricing of quantity options reflects reasonable unit costs even if option quantities may not be exercised.
- Price all CLINs to be profitable independently rather than cross-subsidizing between CLINs.
- Document your pricing rationale to support discussions with evaluators if pricing is questioned.
